Gauging risk in electronic communications regarding accounts in ABDS system

ABSTRACT

A system for communicating electronically over a communications medium regarding an account includes (a) maintaining information pertaining to the account in a database such that the information is retrievable by a unique identifier, the information including security features of a device that generates digital signatures using a private key of a public-private key pair, (b) associating the public key of the device with the unique identifier in the database, (c) receiving an electronic communication including the unique identifier and a digital signature for a message generated by a suspect device (d) authenticating the message using the public key associated with the unique, (e) upon successful authentication of the message, identifying the security features retrievable by the unique identifier as being the security features of the genuine device, and (f) gauging the risk that said generated digital signature was fraudulently sent based on said identified security features of the genuine device.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application claims priority in the United States under 35U.S.C. 120 to international patent application serial numberPCT/US01/41587, filed Aug. 6, 2001, designating the United States andpublished in English, which, in turn, claims priority under 35 U.S.C.119(e), and under the Paris Convention worldwide, to the benefit of thefiling date of Wheeler et al. U.S. provisional patent application Ser.No. 60/223,076, filed on Aug. 4, 2000, both of which are incorporatedherein by reference. This application also incorporates herein byreference each of three international patent applications and three U.S.patent application to Anne and Lynn Wheeler filed concurrently herewithin the U.S. Patent & Trademark Office and bearing Ser. No. 09/923,179(titled “Account-Based Digital Signature (ABDS) System”); serial numberPCT/US01/41562 (titled “Entity Authentication in ElectronicCommunications by Providing Verification Status of Device”) and Ser. No.09/923,075 (titled “Modifying Message Data and Generating Random NumberDigital Signature Within Computer Chip”) collectively referred tohereinafter as the “VS Applications”; serial number PCT/US01/24572(titled “Linking Public Key of Device to Information DuringManufacture”) and Ser. No. 09/923,213 (titled “Manufacturing UniqueDevices That Generate Digital Signatures”); and serial numberPCT/US01/24563 (titled “Trusted Authentication Digital Signature (TADS)System”).

BACKGROUND OF INVENTION

The present invention relates to an improved communication system inwhich electronic communications regarding accounts are digitally signed.

As used herein, an electronic communication (“EC”) is considered to beany communication in electronic form. ECs have become an integral partof transacting business today, especially with the growth of theInternet and e-commerce. An EC can represent, for example, a request foraccess to information or a physical area, a financial transaction, suchas an instruction to a bank to transfer funds, or a legal action, suchas the delivery of an executed contract.

Over recent years, digital signatures also have become an important partof e-commerce. The origination of a digital signature generallycomprises: (1) the calculation of a message digest—such as a hash value;and (2) the subsequent encryption of the message digest. The messagedigest is encrypted by an electronic device generally using a privatekey of a public-private key pair used in asymmetric cryptography. Theresulting ciphertext itself usually constitutes the digital signature,which typically is appended to the message to form the EC. The secondpart of originating the digital signature—encrypting with a privatekey—is referred to herein as “generating” the digital signature, and thecombined two steps (i.e., calculating a message digest and encryptingwith a private key) is referred to herein as “originating” the digitalsignature. Furthermore, while the generation of the digital signature isconventionally understood as the encryption of the message digest, it iscontemplated herein that generating the digital signature also mayinclude simply encrypting the message rather than the message digest.Digital signatures are important because any change whatsoever to themessage in an EC is detectable from an analysis of the message and thedigital signature. In this regard, the digital signature is used to“authenticate” a message contained within the EC (hereinafter referredto as “Message Authentication”).

For example, a message digest may be calculated by applying a hashingalgorithm—such as the SHA-1 algorithm—to the message. Such hashingalgorithm may be applied either within the device or external to thedevice with the resulting hash value then being transmitted to thedevice for generation of the digital signature. In order to perform theMessage Authentication in this example, the recipient of the EC mustknow or be able to obtain both the identity of the hashing algorithmapplied to the message as well as the public key (“PuK”) correspondingto the private key (“PrK”) used to encrypt the message digest. With thisknowledge, the recipient applies the appropriate hashing algorithm tothe message to calculate a hash value, and the recipient decrypts thedigital signature using the public key. If the hash value calculated bythe recipient equals the hash value of the decrypted digital signature,then the recipient determines that the content of the message containedin the EC was not altered in transmission, which necessarily would havechanged the hash value.

In performing Message Authentication, the recipient also authenticatesthe sender of the EC, in so much as the recipient thereby confirms thatthe sender of the EC possessed the private key corresponding to thepublic key used successfully to authenticate the message. This is onetype of entity authentication and is based on what the sender “has”(hereinafter referred to as “Factor A Entity Authentication”). Factor AEntity Authentication is useful when the recipient of the EC has trustedinformation regarding the identity of the owner of the private key.

This trusted information conventionally is provided based on a digitalcertificate issued by a trusted third party that accompanies the digitalsignature and binds the identity (or other attributes) of the privatekey owner with the public key. A digital certificate (also known as a“digital ID”) is a voucher by a third party (commonly referred to as a“Certification Authority”) attesting to the identity (or otherattributes) of an owner of a public key. Essentially, digitalcertificates are the electronic counterparts to driver licenses,passports, membership cards, and other paper-based forms ofidentification. The digital certificate itself comprises an electronicmessage including a public key and the identity of the owner of thepublic key. A digital certificate also typically contains an expirationdate for the public key, the name of the Certification Authority, aserial number of the digital certificate, and a digital signature of theCertification Authority. One of the reasons for an expiration date is tolimit the liability for the Certification Authority due to thelikelihood that attributes other than the identity may change over time.The most widely accepted format for digital certificates is defined bythe CCITT X.509 international standard; thus, certificates can be reador written by any application complying with X.509. Based on a digitalcertificate included in an EC, a recipient is able to authenticate thedigital certificate using a public key of the Certification Authorityand thereby, presumably, confirm the identity of the owner set forththerein.

The system wherein a digital certificate is included in an EC comprisesa “public key infrastructure” (PKI) commonly referred to as the“Certification Authority Digital Signature” (CADS) system. A particularimplementation 100 of the CADS system in the context of an electronictransaction between a purchaser 102 and an online merchant 110 isillustrated in FIG. 1. Under this system, a purchaser 102 using, forexample, a computer 104 creates a purchase order in the form of anelectronic message. The purchaser 102 includes in the message relevantaccount information of a financial institution 112 from which payment isto be made to the merchant 110. The account information includes, forexample, a credit card number and expiration date as well as the name onthe card. Software on the purchaser's computer 104 then originates adigital signature for the message using a private key of the purchaser102 safeguarded in the computer 104. The software also maintains adigital certificate on the computer 104 issued by a CertificationAuthority 106 a. The message, digital signature, and digital certificatethen are combined into an EC, and the EC is communicated over theInternet 108 to the merchant 110.

Upon receipt, the merchant 110 authenticates the message using thepublic key in the digital certificate. If successful, the merchant 110then authenticates the digital certificate using a public key of theCertification Authority 106 a. Successful authentication of the digitalcertificate may satisfy the merchant 110 that the purchaser—the senderof the EC—is the owner identified in the digital certificate. If themerchant 110 is so satisfied, then the merchant 110 submits the accountinformation to the relevant financial institution 112 for an approvalfor payment to the merchant 110 from the account. Upon receipt from thefinancial institution 112 of approval for payment, the merchant 110fills the purchase order of the purchaser 102. Furthermore, confirmationof approval (or rejection) of the purchase order preferably is sent fromthe merchant 110 to the purchaser 102.

Unfortunately, while the CADS system enables two parties who otherwisemay not have a preexisting relationship with one another to communicatewith each other with the confidence of knowing the other's identity, theCADS system does have its drawbacks. For example, a digital certificatetypically is issued with an expiration date, and an expired digitalcertificate generally is not recognized in the industry. Furthermore, ifa private key is lost or stolen, then the owner of the private key mustnotify the Certification Authority to revoke the owner's digitalcertificate; however, a recipient of an EC with a digital certificatewill only know of the revocation of the digital certificate if therecipient cross-references the serial number of the digital certificateagainst a certificate revocation list (CRL) published by theCertification Authority. Another drawback to the CADS system is that thedigital certificate itself is only as good as the particular authoritythat issues it, and it often is necessary to obtain multiple digitalcertificates (i.e., from Certificate Authorities 106 a, 106 b to 106 n)in order to create a sufficient “chain” or “network” of trust betweenthe purchaser 104 and merchant 110 for a transaction or communication tobe accepted and acted upon. Additionally, the entire CADS system restsupon the secrecy of the private key of the Certification Authorityissuing a digital certificate, which, if compromised, collapses the CADSsystem.

In the context of an EC regarding an account, such as the example of anonline purchase set forth above, another drawback of the CADS system isthat the account information must be encrypted or otherwise protected ifsent over an insecure communications medium, such as the Internet 108.In the example above, a hacker eavesdropping on the communication of theaccount information could obtain sufficient information to makefraudulent charges to the account of the purchaser, especially as notall merchants require a digital signature and digital certificate tofill a purchase order. Moreover, financial institutions have yet tostandardize a requirement that a digital certificate of a purchaser besubmitted as a condition precedent to approving a payment request by amerchant; instead, in determining whether a purchaser actually has theauthority to effect payment to a merchant, a financial institutionrelies upon the personal account information provided by the merchant,and whether the account information has been reported lost or stolen.Further, digital certificates raise significant privacy issues in manycircumstances.

Accordingly, a need exists for an improved system of communication usingdigital signatures, especially wherein an EC pertains to an account uponwhich the person (or device) digitally signing the EC has authority toact.

SUMMARY OF INVENTION

Briefly summarized, a method of communicating electronically over acommunications medium regarding accounts includes for each of twoseparate accounts maintained by separate third parties, the steps of:maintaining information pertaining to the account in an account databasesuch that the information is retrievable based on a unique identifier,associating a public key of a public-private key pair with the uniqueidentifier, generating a digital signature for an electronic messageusing a private key of the public-private key pair, the electronicmessage including an instruction and the unique identifier,authenticating the electronic message using the public key associatedwith the information identified by the unique identifier, and upon thesuccessful authentication of the electronic message, executing theinstruction with respect to the account represented by the informationthat is identified by the unique identifier.

The present invention also includes a method of maintaining a CentralKey Authority (CKA) database. The CKA database includes accountinformation of users such as a public key of a user device thatgenerates digital signatures, and third-party account identifiers eachof which identifies to a third-party an account of the user that ismaintained with the third-party and that has been associated with theuser's public key by the third-party.

The present invention also encompasses a method of managing a databasefor identification of security features of a device that generatesdigital signatures, and includes the steps of recording in the databasefor each of a plurality of devices a public key of a pair ofpublic-private keys of the device and information including securityfeatures of the device, the security features being associated with thepublic key in the database; and identifying security features from thedatabase to a recipient of an electronic message for which a digitalsignature was originated utilizing a private key of the public-privatekey pair of a particular one of the devices, the security features beingfor the particular device.

BRIEF DESCRIPTION OF DRAWINGS

Further features and benefits of these aspects of the present inventionwill be apparent from a detailed description of preferred methodsthereof taken in conjunction with the following drawings, wherein likereferences refer to like elements.

FIG. 1 illustrates a prior art Certification Authority DigitalCertificate (CADS) system.

FIG. 2 illustrates a preferred Account-based Digital Signature (ABDS)system in accordance with a first aspect of the present invention.

FIG. 2 a illustrates an account database maintained by an accountauthority for use with an ABDS system.

FIG. 2 b illustrates another account database maintained by an accountauthority for use with an ABDS system.

FIG. 3 illustrates another preferred ABDS system in accordance with thefirst aspect of the present invention.

FIG. 4 a illustrates a flowchart of one embodiment of preferred stepsfor establishing a new ABDS account in accordance with the first aspectof the present invention.

FIG. 4 b illustrates a flowchart of another embodiment of preferredsteps for establishing a new ABDS account in accordance with the firstaspect of the present invention.

FIG. 5 a illustrates a flowchart of one embodiment of preferred stepsfor converting an existing account into an ABDS account in accordancewith the first aspect of the present invention.

FIG. 5 b illustrates a flowchart of another embodiment of preferredsteps for converting an existing account into an ABDS account inaccordance with the first aspect of the present invention.

FIG. 6 illustrates a first business application in accordance with thefirst aspect of the present invention.

FIG. 7 illustrates an account database maintained by an accountauthority for use with the business application of FIG. 6.

FIG. 8 illustrates a flowchart of steps performed by an account holderin the business application of FIG. 6.

FIG. 9 illustrates a flowchart of steps performed by an accountauthority in the business application of FIG. 6.

FIG. 10 illustrates a second business application in accordance with thefirst aspect of the present invention.

FIG. 11 illustrates an account database maintained by an accountauthority for use with the business application of FIG. 10.

FIG. 12 illustrates a flowchart of steps performed by an account holderin the business application of FIG. 10.

FIG. 13 illustrates a flowchart of steps performed by an accountauthority in the business application of FIG. 10.

FIG. 14 illustrates a third business application in accordance with thefirst aspect of the present invention.

FIG. 15 illustrates an account database maintained by an accountauthority for use with the business application of FIG. 14.

FIG. 16 illustrates a flowchart of steps performed by an account holderin the business application of FIG. 14.

FIG. 17 illustrates a flowchart of steps performed by an accountauthority in the business application of FIG. 14.

FIG. 18 illustrates a fourth business application in accordance with thefirst aspect of the present invention.

FIG. 19 illustrates an account database maintained by an accountauthority for use with the business application of FIG. 18.

FIG. 20 illustrates a flowchart of steps performed by an account holderin the business application of FIG. 18.

FIG. 21 illustrates a flowchart of steps performed by an accountauthority in the business application of FIG. 18.

FIG. 22 illustrates a fifth business application in accordance with thefirst aspect of the present invention.

FIG. 23 illustrates an account database maintained by an accountauthority for use with the business application of FIG. 22.

FIG. 24 illustrates a flowchart of steps performed by an account holderin the business application of FIG. 22.

FIG. 25 illustrates a flowchart of steps performed by an accountauthority in the business application of FIG. 22.

FIG. 26 illustrates a sixth business application in accordance with thefirst aspect of the present invention.

FIG. 27 illustrates an account database maintained by an accountauthority for use with the business application of FIG. 26.

FIG. 28 illustrates a flowchart of steps performed by an account holderin the business application of FIG. 26.

FIG. 29 illustrates a flowchart of steps performed by an accountauthority in the business application of FIG. 26.

FIG. 30 illustrates a seventh business application in accordance withthe first aspect of the present invention.

FIG. 31 illustrates an account database maintained by an accountauthority for use with the business application of FIG. 30.

FIG. 32 illustrates a flowchart of steps performed by an account holderin the business application of FIG. 30.

FIG. 33 illustrates a flowchart of steps performed by an accountauthority in the business application of FIG. 30.

FIG. 34 illustrates an eighth business application in accordance withthe first aspect of the present invention.

FIG. 35 illustrates an account database maintained by an accountauthority for use with the business application of FIG. 34.

FIG. 36 illustrates a flowchart of steps performed by an account holderin the business application of FIG. 34.

FIG. 37 illustrates a flowchart of steps performed by an accountauthority in the business application of FIG. 34.

FIG. 38 illustrates a ninth business application in accordance with thefirst aspect of the present invention.

FIG. 39 illustrates an account database maintained by an accountauthority for use with the business application of FIG. 38.

FIG. 40 illustrates a flowchart of steps performed by an account holderin the business application of FIG. 38.

FIG. 41 illustrates a flowchart of steps performed by an accountauthority in the business application of FIG. 38.

FIG. 42 illustrates a tenth business application in accordance with thefirst aspect of the present invention.

FIG. 43 illustrates an account database maintained by an accountauthority for use with the business application of FIG. 42.

FIG. 44 illustrates a flowchart of steps performed by an account holderin the business application of FIG. 42.

FIG. 45 illustrates a flowchart of steps performed by an accountauthority in the business application of FIG. 42.

FIG. 46 illustrates an eleventh business application in accordance withthe first aspect of the present invention.

FIG. 47 illustrates an account database maintained by an accountauthority for use with the business application of FIG. 46.

FIG. 48 illustrates a flowchart of steps performed by an account holderin the business application of FIG. 46.

FIG. 49 illustrates a flowchart of steps performed by an accountauthority in the business application of FIG. 46.

FIG. 50 illustrates a first business application in accordance withanother preferred embodiment of the first aspect of the presentinvention.

FIG. 51 illustrates an account database maintained by an accountauthority for use with the business application of FIG. 50.

FIG. 52 illustrates a flowchart of steps performed by an account holderin the business application of FIG. 50.

FIG. 53 illustrates a flowchart of steps performed by an intermediateparty in the business application of FIG. 50.

FIG. 54 illustrates a flowchart of steps performed by an accountauthority in the business application of FIG. 50.

FIG. 55 illustrates a second business/consumer application in accordancewith another preferred embodiment of the first aspect of the presentinvention.

FIG. 56 illustrates an account database maintained by an accountauthority for use with the business application of FIG. 55.

FIG. 57 illustrates a flowchart of steps performed by an account holderin the business application of FIG. 55.

FIG. 58 illustrates a flowchart of steps performed by an intermediateparty in the business application of FIG. 55.

FIG. 59 illustrates a flowchart of steps performed by an accountauthority in the business application of FIG. 55.

FIG. 60 illustrates a third business/consumer application in accordancewith another preferred embodiment of the first aspect of the presentinvention.

FIG. 61 illustrates an account database maintained by an accountauthority for use with the business application of FIG. 60.

FIG. 62 illustrates a flowchart of steps performed by both an accountholder and merchant (intermediate party) in the business application ofFIG. 60.

FIG. 63 illustrates a flowchart of steps performed by an accountauthority in the business application of FIG. 60.

FIG. 64 illustrates a preferred ABDS system in accordance with a secondaspect of the present invention.

FIG. 64 a illustrates an account database maintained by an accountauthority for use with the system of FIG. 64.

FIG. 64 b illustrates another account database maintained by an accountauthority for use with the system of FIG. 64.

FIG. 64 c illustrates a third account database maintained by an accountauthority for use with the system of FIG. 64.

FIG. 65 illustrates a flowchart of steps performed by an account holderin the system of FIG. 64.

FIG. 66 illustrates a flowchart of steps performed by an accountauthority in the system of FIG. 64.

FIG. 67 illustrates another preferred ABDS system in accordance with asecond aspect of the present invention.

FIG. 68 illustrates a flowchart of steps performed by an account holderin the system of FIG. 67.

FIG. 69 illustrates a flowchart of steps performed by an intermediateparty in the system of FIG. 67.

FIG. 70 illustrates a flowchart of steps performed by an accountauthority in the system of FIG. 67.

FIG. 71 a illustrates a preferred ABDS system in accordance with a thirdaspect of the present invention.

FIG. 71 b illustrates another preferred ABDS system in accordance withthe third aspect of the present invention.

FIG. 71 c illustrates yet another preferred ABDS system in accordancewith the third aspect of the present invention.

FIG. 71 d illustrates a further preferred ABDS system in accordance withthe third aspect of the present invention.

FIG. 72 illustrates an account database maintained by an accountauthority for use with the system of FIG. 71 a.

FIG. 73 illustrates a flowchart of steps performed by an accountauthority in accordance with the fourth aspect of the present invention.

FIG. 74 illustrates use of an EC for session authentication andtransaction authentication purposes in accordance with the first aspectof the present invention.

FIG. 75 illustrates use of an EC for transaction confirmation purposesin accordance with the first aspect of the present invention.

FIG. 76 illustrates an electronic communication format or layout inaccordance with the various aspects of the present invention.

DETAILED DESCRIPTION

As a preliminary matter, it readily will be understood by those personsskilled in the art that, in view of the following detailed descriptionof the devices, systems, and methods of the present invention, thepresent invention is susceptible of broad utility and application. Manyembodiments and adaptations of the present invention other than thoseherein described, as well as many variations, modifications, andequivalent arrangements, will be apparent from or reasonably suggestedby the present invention and the following detailed description thereof,without departing from the substance or scope of the present invention.Accordingly, while the present invention is described herein in detailin relation to preferred embodiments, it is to be understood that thisdetailed description only is illustrative and exemplary of the presentinvention and is made merely for purposes of providing a full andenabling disclosure of the present invention. The detailed descriptionset forth herein is not intended nor is to be construed to limit thepresent invention or otherwise to exclude any such other embodiments,adaptations, variations, modifications and equivalent arrangements ofthe present invention, the present invention being limited solely by theclaims appended hereto and the equivalents thereof.

Those skilled in the art will understand and appreciate that thesequence(s) and/or temporal order of the steps of various processesdescribed and claimed herein are those considered by the inventors to bethe best mode contemplated by them for carrying out the inventions. Itshould also be understood that, although steps of various processes areshown and described in some cases as being in a preferred sequence ortemporal order, the steps of such processes are not limited to beingcarried out in any particular sequence or order, absent a specificindication that a step or steps should be carried out in a particularsequence or order to achieve a particular intended result. In mostcases, the steps of such processes may be carried out in variousdifferent sequences and orders, while still falling within the scope ofthe present inventions.

Accordingly, while much of the present invention is described in detailherein with respect to computers, networks, integrated circuits,computer chips, and devices, no specific software or logic circuit isintended nor is required to be used in the practicing of the presentinvention. Indeed, it would be a matter of routine skill to selectappropriate computers, networks, integrated circuits, computer chips,and devices in implementing the invention in a particular businessapplication.

The present invention broadly comprises the association of a public keyof a device that originates digital signatures using asymmetriccryptography to other information in an account database record. Ingeneral, a method in accordance with the first aspect of the presentinvention includes electronically communicating a message over acommunications medium regarding an account that is associated with apublic key, the corresponding private key of which is used to digitallysign the message. A method in accordance with the second aspect of thepresent invention includes associating multiple accounts with the samepublic key. A method in accordance with the third aspect of the presentinvention includes maintaining a central database of information on allaccounts associated with the same public key. Finally, a method inaccordance with the fourth aspect of the present invention includesapplying dynamic risk analysis to a specific message to gauge the riskthat the digital signature for the message was fraudulently originatedand, thus, to determine whether or not to perform an instructioncontained within the message.

As used herein, an “account holder” is generally any person possessing adevice that is capable of generating a digital signature using a privatekey retained therein; the private key corresponding with a public keyassociated with an account upon which the person is authorized to act.An “account authority” is generally a person, entity, system, orapparatus that maintains such an account on behalf of the accountholder. In some embodiments, the “account holder” is, itself, a devicethat is capable of generating a digital signature using a private keyretained therein; the private key corresponding with a public keyassociated with an account upon which the device is authorized to act.

Having briefly described the methodologies of the various aspects of thepresent invention, general and specific implementations of two-party,three-party, and multiple-party Account-based Digital Signature (ABDS)systems now will be described in greater detail.

1. Account-Based Digital Signature (ABDS) Systems

a. General 2-Party ABDS Systems

FIG. 2 illustrates a preferred Account-based Digital Signature (ABDS)system 200 in accordance with a first aspect of the present invention.Specifically, FIG. 2 illustrates a two-party ABDS system that includesan account holder 202 and an account authority 212. As shown, theaccount holder 202 comprises a person who possesses a device 250, whichsecurely protects a unique private key of a public-private key pairtherein. The account authority 212 comprises an entity or system thatmaintains one or more account databases, collectively referred to andillustrated by account database 214, which includes an account of theaccount holder 202. Preferably, the account is identifiable within theaccount database 214 based on a unique identifier (acctID) 216, such asan account number. Further, the account authority 212 maintains anassociation between the account and the public key 218, whichcorresponds with the private key that is securely retained within thedevice 250 of the account holder 202.

Communications between the account holder 202 and account authority 212regarding the account of the account holder 202 occur through anyconventional communications medium 208, such as the Internet, anintranet, a wireless network, a dedicated hardwired network, or thelike. Each communication is electronic, and each electroniccommunication (“EC”) 206 from the account holder 202 to the accountauthority 212 includes an electronic message (M) that is digitallysigned by the account holder 202 using the private key retained withinthe device 250. The means by which the device 250 communicates with theaccount authority 212 varies by the form factor of the device 250 andwhether or not the device 250 is used in conjunction with a separate I/Osupport element (not shown) to assist in the generation or creation ofthe message, in the transmission or communication of the EC to theaccount authority 212, or both.

The message preferably includes the unique identifier (acctID) 216 ofthe account of the account holder 202 and an instruction (i1) for theaccount authority 212 to perform in relation to the account. The digitalsignature of the message also preferably includes a unique random numberor session key, such as, for example, a date and time stamp, so that notwo digital signatures originated by the device 250 would ever beidentical (and also so that any duplicate digital signature received bythe account authority 212 could be identified as such and disregarded).

Using the unique identifier (acctID) 216, the account authority 212 isable to retrieve the associated public key 218, which is necessary forauthenticating the message and the sender of the EC 206 (i.e., based onFactor A Entity Authentication). In accordance with this first aspect ofthe present invention, upon the successful authentication of the messageand of the sender of the EC 206, the account authority 212 performs (orattempts to perform) the instruction (i1) of the message as if theaccount holder 202 had presented such instruction (i1) in person.

Advantageously, since the unique identifier (acctID) 216 is all thatmust be included in the message in order for the account authority 212to retrieve the appropriate public key 218 from the account database 214for the purpose of authenticating the message and sender of the EC 206and for having sufficient authorization from the account holder 202 forperforming the instruction (i1) contained in the message, the accountholder 202 need not include any “identity” information in the message.In addition, since the account authority 212 preferably will not performany action on the account of the account holder 202 without a validdigital signature originated by the device 250 (or, alternatively,without the actual, physical presence of the account holder 202) andsince no “identity” information needs to be included in electroniccommunications between the account holder 202 and the account authority212 regarding the account, such electronic communications, including EC206, may be transmitted in unencrypted fashion over an insecurecommunications medium 208 (such as the Internet) without risk ofcompromising the privacy of the account holder 202. Obviously, if theaccount holder 202 desires to protect the contents of the informationcontained within the EC 206 for privacy, confidentiality, or similarreasons, the EC 206 may be encrypted by the account holder 202 inconventional manner, for example, using the public key of the accountauthority 212 for PGP-type encryption, using secure socket layering(SSL), or other similar encryption techniques; however, encrypting thecontents of the EC is not necessary for the functioning of the presentinvention.

FIG. 2 a illustrates a plurality of possible relationships among theinformation contained within account database 214. Generally, eachaccount within the database 214, for example, is identified by itsaccount identifier (acctID) 216 and has associated therewith accountinformation 240, such as information specific to the account holder(hereinafter “customer-specific information”) and information specificto the account (hereinafter “account-specific information”), and publickey information 218. At a minimum, the public key information 218identifies each public key (PuK) associated with each particular accountand/or account identifier 216. As shown, database 214 maintains aplurality of specific accounts 281,282,283,284,285,288, with a pluralityof accounts (not shown but indicated by the “ . . . ”) existing betweenaccounts 285 and 288. Accounts 281,288 illustrate a first account setuptype in which each account has a single customer or account holder andin which each account has a single public key (PuK) associated for usetherewith. Account 282 illustrates a second account setup type in whichthe account 282 has a single customer or account holder associatedtherewith, but the account holder has a plurality (two, in this case) ofdifferent public keys (PuK) associated for use with the account 282.Such a setup is beneficial, for example, when an account holder usesmore than one device of the present invention for access to the sameaccount 282. A third account setup type is illustrated in associationwith accounts 283,284. Each of these accounts 283,284 has the sameaccount holder, who uses a single public key to access either or both ofthese accounts 283,284. Such a setup is beneficial, for example, when anaccount holder maintains a plurality of accounts (in this case, two)with a single account authority (e.g., primary and secondary bankaccounts with the same financial institution). This particular setup isdiscussed in greater detail in the “person-centric device” section setforth herein with regard to FIGS. 64–70. A fourth account setup type isillustrated in association with account 285. Account 285 has associatedtherewith a plurality of different customers or account holders (three,in this case), each of whom has a different public key (PuK) foraccessing the account 285. Such a setup is beneficial, for example, whenan account has two or more authorized users (e.g., husband and wife withaccess to a joint account; plurality of employees with access to theiremployer's account). A specific business implementation using this typeof account setup is illustrated and discussed in association with FIGS.46–49.

Although not shown in FIG. 2 a, it should be apparent that the abovefour account setup types may be further combined with each other in avariety of permutations and still fall within the scope and intent ofthe present invention. As one example of such a combination not shown inFIG. 2 a, one of the customers accessing account 285 could, in fact,have more than one public key for accessing the joint account 285.

Turning now to FIG. 2 b, in a further feature of the present invention,account database 214 may also include Device Profile Information 270.Each Device Profile includes the Security Profile and transactionalhistory of the device. The Security Profile includes the securityfeatures and manufacturing history of the device. The security featuresinclude those features of the device that protect the private key andother data within the device from discovery (“Security Characteristics”)and features that perform entity authentication (“AuthenticationCapabilities”). Information contained in the Security Profile isdescribed in greater detail herein in Section VI.4, entitled “ApplyingDynamic Risk Analysis to a Transaction.” Since it is contemplated that aunique private key associated with the corresponding public key 218maintained with the account database 214 only exists in a single deviceof the present invention, there is a one-to-one correspondence betweeneach public key 218 and its respective device profile information 270.Further, additional security is obtained with a device that is incapableof divulging its private key.

b. General 3-Party ABDS Systems

FIG. 3 illustrates a preferred three-party ABDS system 300 and includesan account holder 302 and account authority 312 as well as anintermediate party 310. The three-party ABDS system 300 differs from thetwo-party ABDS system 200 (from FIG. 2) in that the message and digitalsignature from the account holder 302 to the account authority 312 iscommunicated first to the intermediate party 310 by means of an EC 305.The intermediate party 310 then forwards the same message and digitalsignature in another EC 315 to the account authority 312.

An instruction (i2) is communicated from the account holder 302 to theintermediate party 310, either as part of the EC 305 or as a separate EC(not shown). The intermediate party 310 does not act upon theinstruction (i2) but rather, forwards the EC 315 to the accountauthority 312 and waits for the account authority 312 to approve orreject the message. As shown, the message and digital signature in EC315 are the same as the message and digital signature in EC 305.

Upon receipt of the EC 315, the account authority 312 attempts toauthenticate the message and the sender of EC 305 using the public keyof the public-private key pair, which is retrieved from the accountdatabase 314 based on the unique identifier (acctID) 316 from themessage. If the authentication is successful, the account authority 312performs (or attempts to perform) the instruction (i1) of the message asif the account holder 302 were presenting the instruction (i1) inperson. Based on the results of the attempted authentication of themessage and the sender of the EC and based on the attempted execution ofinstruction (i1), the account authority 312 provides the intermediateparty 310 with notification of approval or rejection of the message bymeans of a reply EC 319. If reply EC 319 indicates an approval of themessage, the intermediate party 310 then executes the instruction (i2)received from the account holder 302. Preferably, the intermediate party310 then notifies the account holder 302 either of the approval andexecution of instruction (i2) or of the rejection of the instruction(i2) by means of reply EC 309.

Again, it should be noted that no “identity” information needs to beincluded in the EC 305 by the account holder 302 under this system 300.In addition, all of the ECs 305,315,309,319 may be transmitted inunencrypted fashion over any conventional communications mediums 308a,308 b, such as the Internet, an intranet, a wireless network, adedicated hardwire network, and the like, for the same reasons discussedabove with regard to system 200 in FIG. 2. Also, as discussed above, ifthe parties desire to protect the contents of the information containedwithin the various ECs 305,309,315,319 for privacy, confidentiality, orsimilar reasons, such ECs may be encrypted by the sender of theparticular EC in conventional manner, for example, using the public keyof the intended recipient(s) of the particular EC for PGP-typeencryption, using secure socket layering (SSL), or other similarencryption techniques; however, encrypting the contents of the variousECs is not necessary for the functioning of the present invention.Further, the communication mediums 308 a,308 b may be different fromeach other (as illustrated) or part of the same medium.

c. Multiple-Party ABDS Systems

Although not shown specifically in FIGS. 2 and 3, it should beunderstood that one or more additional parties or entities may beintroduced along the communication route between the account holder,intermediate party, and account authority within the scope of thepresent invention. Among other things, such additional parties may beuseful for expediting, screening, and correctly routing electroniccommunications between the various account holders, intermediateparties, and account authorities.

d. General Account Set-Up in ABDS Systems

Of course, before either ABDS system 200,300 is utilized in practice,the account holder 202,302 first must establish an ABDS account with theappropriate account authority 212,312. The steps involved inestablishing a new ABDS account are set forth in FIGS. 4 a and 4 b. Thesteps involved in converting a pre-existing (and conventional) accountinto an ABDS account are set forth in FIGS. 5 a and 5 b.

i. Establishing a New ABDS Account

Referring first to FIG. 4 a, one exemplary process of establishing a newaccount within the ABDS system is illustrated. In this particularembodiment, the process is initiated by an account authority. Forexample, the account authority first establishes (Step 402) a “shell”account for a prospective account holder using publicly availableinformation about the prospective account holder, such as name andaddress. The account authority next assigns (Step 404) a unique accountidentifier to the “shell” account and associates it therewith. Theaccount authority then obtains (Step 406) the public key from a deviceof the present invention and records (Step 408) the public key in theaccount database and associates it with the “shell” account or with theunique identifier. In some embodiments of the present invention, theunique identifier may actually be the public key from the device or ahashed version of the public key. The account authority then distributesor sends (Step 410) the device that retains the private keycorresponding with the public key associated with the “shell” account tothe prospective account holder with an offer to “open” an account onbehalf of the prospective account holder with the account authority andwith instructions for doing so. The account authority then waits for aresponse from the prospective account holder.

If a response is received (Step 412), the account authority usesconventional authentication techniques to confirm that it iscommunicating with the prospective account holder. The account authoritythen obtains (Step 414) additional information, as needed, to populatethe account record. The account authority then requires (Step 416) theprospective account holder to transmit a test message that is digitallysigned using the device. Such test message confirms that the prospectiveaccount holder possesses the correct device. If the test messageconfirms, then the device is “activated” (Step 418) for use with theassociated account.

In an alternative embodiment, setup of a new ABDS account may beinitiated by a prospective account holder who already possesses a deviceof the present invention, as illustrated in FIG. 4 b. For example, anaccount authority may receive (Step 450) a request to establish a newABDS account from such a prospective account holder. If the accountauthority is willing to accept such a prospective account holder whoalready possesses such a device, the account authority receives (Step452) sufficient information from the prospective account holder toestablish such an account. In some business applications, it is notnecessary for the prospective account holder to divulge any “identity”information in order to establish such an account. The account authoritythen records (Step 454) whatever information is provided by theprospective account holder in a record of the account database of theaccount authority and assigns (Step 456) a unique identifier, such as anaccount number, to the account.

Next and preferably contemporaneously, the account authority obtains(Step 458) the public key that corresponds with the private key that issecurely retained on the device. In some business applications, thepublic key is obtained directly from the device in response to asuitable request submitted to the device. In other businessapplications, the public key is obtained from a database maintained by athird party, such as a Central Key Authority (as discussed below withreference to FIGS. 71 a–72), device manufacturer, device distributor, orthe like. The account authority then records (Step 460) the public keyin such a manner that the public key is suitably bound to or associatedwith the account record of the prospective account holder. Preferably,the public key is associated particularly with the unique identifier ofthe account. In some embodiments, the public key itself (or a hashedvalue of the public key) is used as the unique identifier assigned tothe account.

Finally, it also is preferable for the account authority to confirmproper binding of the public key to the account and to confirm that thedevice retains the private key, which corresponds with the public keybound to the account, by having the account holder submit (Step 462) a“test” EC for authentication, which may contain the corresponding publickey being registered. Once the account authority is satisfied that theaccount has been established properly and that the account holderpossesses the device retaining the appropriate private key correspondingwith the public key being registered, the account is activated (Step464) so that transactions that are digitally signed using the devicewill be deemed to have come from the legitimate account holder accordingto Factor A Entity Authentication.

In the above embodiment, the account authority may desire to confirmthat the integrity level of the device, as confirmed by the SecurityProfile of the device obtained from the Central Key Authority or otherreliable source or as confirmed by a physical inspection of the device,meets or exceeds its business standards or requirements for use with therespective account.

ii. Converting a Pre-Existing Account Into an ABDS Account

Referring now to FIG. 5 a, an exemplary process of converting apre-existing, conventional account into an ABDS account, when initiatedby an account authority, is set forth. First, it is assumed that theaccount authority already maintains a conventional account setup for theaccount holder in a record of an account database. Further, such recordcontains personal and other pertinent account information of the accountholder. It is also assumed that the existing account already has its ownunique identifier.

First, the account authority obtains (Step 502) the public key from adevice of the present invention and records (Step 504) the public key inthe account database and associates it with the existing account or withthe unique identifier of the account. The account authority thendistributes or sends (Step 506) the device that retains the private keycorresponding with the public key associated with the existing accountto its account holder with an offer to “convert” the existingconventional account to an ABDS account. The account authority thenwaits for a response from its account holder.

If a response is received (Step 508), the account authority usesconventional authentication techniques to confirm that it iscommunicating with its expected account holder. The account authoritythen requires (Step 510) the account holder to transmit a test messagethat is digitally signed using the device. Such test message confirmsthat the account holder possesses the correct device. If the testmessage confirms, then the device is “activated” (Step 512) for use withthe newly converted ABDS account.

In an alternative embodiment, conversion of a conventional account to anABDS account may be initiated by an existing account holder who alreadypossesses a device of the present invention. For example, the accountauthority receives (Step 550) a request to convert a conventionalaccount into an ABDS account, which enables the account holder totransact business on the account using electronic messages digitallysigned using the account holder's specified device. If the accountauthority is willing to accept such a conversion and is willing to allowthe account holder to use such a device, the account authority firstconfirms (Step 552), using conventional entity authenticationtechniques, that it is communicating or otherwise dealing with theexpected account holder. Next and preferably contemporaneously, theaccount authority obtains (Step 554) the public key that correspondswith the private key that is securely retained on the device. In somebusiness applications, the public key is obtained directly from thedevice in response to a suitable request submitted to the device. Inother business applications, the public key is obtained from a databasemaintained by a third party, such as a Central Key Authority (asdiscussed below with reference to FIGS. 71 a–72, device manufacturer,device distributor, or the like. The account authority then records(Step 556) the public key in such a manner that the public key issuitably bound to or associated with the existing account record of itsaccount holder. Preferably, the public key is associated particularlywith the unique identifier of the account. In some embodiments, thepublic key itself (or a hashed value of the public key) is used as theunique identifier assigned to the account.

Finally, it also is preferable for the account authority to confirmproper binding of the public key to the account and to confirm that thedevice retains the private key, which corresponds with the public keybound to the account, by having the account holder submit (Step 558) a“test” EC for authentication, which may contain the corresponding publickey being registered. Once the account authority is satisfied that theaccount has been established properly and that the account holderpossesses the device retaining the appropriate private key correspondingwith the public key being registered, the account is activated (Step560) so that transactions that are digitally signed using the devicewill be deemed to have come from the legitimate account holder accordingto Factor A Entity Authentication.

e. Devices Useful With ABDS Systems

In accordance with all of the aspects of the present invention, thedevice comprises hardware, software, and/or firmware, and specificallycomprises a computer chip, an integrated circuit, a computer-readablemedium having suitable software therein, or a combination thereof. Thedevice further may comprise a physical object such as a hardware tokenor an embedded token, the token containing such a computer chip,integrated circuitry, or software, or combination thereof. If the deviceis a hardware token, it preferably takes the form of a ring or otherjewelry; a dongle; an electronic key; a card, such as an IC card, smartcard, debit card, credit card, ID badge, security badge, parking card,or transit card; or the like. If the device is an embedded token, itpreferably takes the form of a cell phone; a telephone; a television; apersonal digital assistant (PDA); a watch; a computer; computerhardware; or the like. The device preferably includes a device interfacecomprising a port—including a wireless communications port, a serialport, a USB port, a parallel port, or an infrared port—or some otherphysical interface for communicating with an external electronicapparatus, whether contact or contactless. The device also may include atrusted platform module (TPM) comprising hardware and softwarecomponents providing increased trust in a platform, as set forth anddescribed in Trusted Platform Module (TPM) Security Policy Version 0.45,TRUSTED COMPUTING PLATFORM ALLIANCE, October 2000, and TCPA PCImplementations Specification Version 0.95, TRUSTED COMPUTING PLATFORMALLIANCE, Jul. 4, 2001, both which are incorporated herein by reference(collectively “TCPA Documents”).

Preferably, the device is capable of receiving an electronic message andthen originating a digital signature for the electronic messageutilizing the private key stored therein. The device preferably alsoperforms a hash function on the message received by the device prior toencryption with the private key.

Additionally, it is preferred that the device include a deviceinterface, such as, for example, an alphanumeric keypad, an electricalcontact, a touch screen display, a standard electronic interface with acomputer bus, or an antenna, so that the device not only may receive amessage, but also compose a message. The device interface may alsocomprise a port, such as a wireless communications port, a serial port,a USB port, a parallel port, or an infrared port.

Some of the above devices require use of an I/O support element toenable the device to receive messages or other input. Some of thedevices require use of an I/O support element to transmit information,including digital signatures and messages to recipients of the ECs. Someof the devices are self-contained, which means that they can generateand transmit messages, digital signatures, and other information withoutthe use of external apparatuses; some devices, although self-contained,are capable of interacting with such external apparatuses, such as anI/O support element, if desired. An I/O support element may take theform of any number of different apparatuses, depending upon theparticular application in which it is used and depending upon the formfactor of device with which it interacts. One example of an I/O supportelement includes a card reader comprising hardware and softwarecomponents designed in accordance with the technical specificationspublished by CEN/ISSS as a result of their Financial Transactional ICCard Reader Project (known commonly as “FINREAD”).

With regard to the security of the device used in each aspect of thepresent invention, preferably during the manufacture of the device, aunique and random public-private key pair is generated directly withinthe device (using a random number generator), preferably on a computerchip, integrated circuit, or other cryptographic module embeddedtherein, using known manufacturing techniques. Because of the size ofthe private key and because the key is generated using a random numbergenerator, the likelihood that a duplicate private key might exist in adifferent device is very low. The private key then is securely storedwithin a memory location in the device and, preferably, madeinaccessible throughout the life of the device (other than for thepurpose of generating a digital signature internally within the device).Furthermore, the device preferably includes the following additionalcharacteristics: it is tempested (i.e., designed in such a way tominimize electromagnetic emanations from the device and, thus, minimizeits vulnerability to electronic eavesdropping); the device is immune toknown electronic attacks; the device is tamper-resistant withzeroization capability (i.e., physical tampering or intrusion of thedevice should destroy the functionality of the digital signaturecomponent of the device and/or erase the private key); the devicemaintains the private key securely such that the private key is neverdivulged outside of the device; and the device allows export of thepublic key when necessary.

Furthermore, the device preferably originates digital signatures inaccordance with an elliptical curve digital signature algorithm (ECDSA)as specified in Federal Information Processing Standards Publication186-2, Digital Signature Standard, US DOC/NBS, Jan. 11, 1994(hereinafter “FIPS PUB 186-2”), which is incorporated herein byreference. Accordingly, the device originates digital signatures using arandom number generator, and the hash function is performed using thesecure hash algorithm (“SHA-1”), which generates a 20-byte outputregardless of the size of the message that is input into the device. TheSHA-1 itself is specified in Federal Information Processing StandardsPublication 180-1, Secure Hash Standard, US DOC/NBS, Apr. 17, 1995(hereinafter “FIPS PUB 180-1”), which is hereby incorporated byreference.

In the aspects of the invention, the device preferably is personalizedto its authorized user(s). Personalization of the device includes theestablishment of a personal identification number (PIN), password, orpassphrase (hereinafter “Secret”). Conventionally, such a Secret isprestored within the device and must be input into the device before itwill operate to generate digital signatures. Alternatively, but alsoconventionally, the Secret is shared with the recipient beforehand and,when the EC later is sent to the recipient, the Secret also is sent tothe recipient in association with the message. In the first case,verification of the Secret authenticates the user of the device(hereinafter “User Authentication”), and in the second case,verification of the Secret authenticates the sender of the EC(hereinafter “Sender Authentication”). If the Secret is shared andtransmitted between the sender of an EC and the recipient, it typicallymust be encrypted or otherwise protected to maintain its secrecy fromothers. In either case, confirmation of the Secret represents entityauthentication based on what the user or sender “knows” (hereinafter“Factor B Entity Authentication”).

Other security measures against fraudulent use of the device throughphysical theft include the verification of a biometriccharacteristic—like a fingerprint, retina scan, DNA, voice print, andthe like—of the user of the device or sender of the EC. This type ofauthentication is based on what the user or sender “is” (hereinafter“Factor C Entity Authentication”). As with the Secret, a biometric valueis conventionally either maintained within the device for UserAuthentication, or is shared with the recipient beforehand for SenderAuthentication by the recipient. If the biometric value is shared andtransmitted between the sender of an EC and the recipient, even greaterprecautions must be taken to protect such biometric value frominterception and discovery by others.

In contrast with both of the above methods of providing Factor B andFactor C Entity Authentication information to the recipient of the EC,an alternative method of providing Entity Authentication status from theaccount holder to the account authority in which the Secret and/orbiometric value(s) is provided to the device and an indicatorrepresenting the results of the comparison of such Secret and/orbiometric value(s) with data prestored in the device is provided to therecipient of the EC without communicating or compromising the Secretand/or biometric value(s) may also be used with the present invention.Such a methodology is described in greater detail in the VSApplications.

f. Types of and Uses for ECs in an ABDS System

As stated previously with regard to both FIGS. 2 and 3, an EC from anaccount holder to an account authority preferably includes both amessage (M) and a digital signature of the message (DS(M)). The messagepreferably includes the unique account identifier (acctID) and aninstruction (i1) for the account authority to perform in relation to theaccount. In many circumstances, however, it is not necessary for themessage to contain the unique account identifier. For example, theaccount authority may have already obtained the unique accountidentifier from a previous message from the account holder andretransmission of the account identifier is unnecessary for a follow-upmessage from the same account holder as long as the account authorityknows that it is communicating with the same account holder (e.g., bymeans of a session key or identifier or during a continuous,uninterrupted electronic connection between the two). Further, it is notalways necessary for the message to contain an instruction (i1), suchas, for example, when the instruction (i1) is implicit in the merecommunication between the account holder and the account authority(e.g., an instruction (i1) in an EC sent to a parking gate controllerobviously implies an instruction to “open the parking gate”).

ECs, and the ability to authenticate the sender of an EC, are useful forat least three different business purposes within the present invention.These three different purposes are described generally hereinafter as“session authentication,” “transaction authentication,” and “transactionconfirmation.” Session authentication and transaction authentication aresimilar to each other since both typically involve situations in whichthe account holder must “prove” (at least to the extent possible basedon the strength of the entity authentication) to the account authoritythat he is the legitimate account holder. In contrast, transactionconfirmation typically involves situations in which the account holderhas already proven to the account authority that he is the legitimateaccount holder; however, the account authority requires confirmation ofa specific digitally-signed message from the account holder before theaccount authority will perform a requested action (typically, upon theaccount itself) in response to a specific instruction (i1) containedwithin the message.

Session authentication and transaction authentication are generallynecessary before the account authority will grant the account holderwith access to the account of the account holder or to another resourceto which the account holder has rights. Such authentication is alsogenerally necessary before the account authority will perform arequested action on the account or resource. A resource is, for example,a physical space, database, computer file, data record, checkingaccount, computer system, computer program, web site, or the like. Amain distinction between session authentication and transactionauthentication is what the account authority does as a result of suchauthentication. For example, once the account holder is authenticatedfor session authentication purposes, the account authority provides theaccount holder with access (by means of a session key, entityidentifier, and the like) to the requested account or resource for theduration of the “session.” The meaning of a session varies dependingupon the type of account or resource being accessed and depending uponthe business rules of the particular account authority protecting theaccount or resource; however, a session typically means some period oftime during which the account holder is allowed to perform actions on orwithin the account or resource without providing additionalauthentication to the account authority. In addition, the amount ofaccess to the account or resource an account holder is granted is alsogoverned by the business rules of the particular account authority andmay vary from account authority to account authority and from account toaccount.

In contrast, transaction authentication is typically only useful for theparticular transaction with which it is associated. Transactionauthentication associated with a particular transaction is not “carriedover” for use with another transaction. Such a transaction may be arequest for the account authority to perform a specific action on theaccount or resource (e.g., a request for the account authority to“provide checking account balance” or “open the door”). In contrast withtransaction confirmation (described in the next paragraph), however,transaction authentication is useful when the account authority does notspecifically need to know the “intent” of the account holder beforeperforming the requested action.

Transaction confirmation, on the other hand, is useful when the value orrisk associated with a particular transaction rises to the level thatthe account authority will not act unless it receives sufficientassurance that the account holder intended to send and digitally signthe message and, corresponding, intended for the account authority toact in reliance thereupon. Since a digital signature is capable of beinggenerated by a device, potentially without the desire or even knowledgeof the owner or user of the device, intent cannot be presumed from themere receipt of a digital signature from a device of the account holder.For this reason, some means of confirming the account holder's intentwith respect to a specific transaction is needed. Such transactionconfirmation is preferably obtained by a physical, overt act performedby the account holder that is determinable within the message receivedby the account authority. For example, in some instances, thecontemporaneous provision of Factor B or C entity authenticationinformation by the account holder in conjunction with the message thatis digitally signed can imply confirmation or intention. Another methodof obtaining such transaction confirmation is through the deliberate andrecognizable modification by the account holder of a “proposed” messagegenerated by the account authority, which is then digitally signed bythe account holder.

In light of the above, it should be understood that in manycircumstances, even if the account holder has already provided entityauthentication information for the purpose of session authentication, itmay be necessary for the account holder to provide additional and/orstronger entity authentication information (still for sessionauthentication purposes) before the account authority will provide theaccount holder, for example, with access to a more restricted portion ofthe particular account or resource or to another more restricted accountor resource. Further, it should also be understood that even during aparticular session, it may be necessary for the account holder toprovide entity authentication information to the account authorityeither for transaction authentication purposes (when the transactionrequires a stronger level of entity authentication than the particularsession required) or for transaction confirmation purposes (when theaccount authority desires specific assurance of the account holder'sintent before performing the requested action). In addition, it shouldalso be understood that a single EC communicated from an account holderto an account authority may be used simultaneously for both transactionauthentication and for transaction confirmation purposes in manycircumstances.

Turning now to FIG. 74, an example of an EC 7406 used for sessionauthentication purposes is illustrated. As shown, an account authority7412 acts as a type of “gate-keeper” for three resources 7440,7450,7460,one of which the account holder 7402 desires to access as requested inthe EC 7406. Although only one account authority 7412 is illustrated inthis example for ease of reference, it should be understood that eachresource 7440,7450,7460 could, in fact, have its own separate accountauthority (not shown) associated therewith.

Continuing with FIG. 74, the account authority 7412 restricts access tothe resources 7440,7450,7460, directly or indirectly, by preventing theaccount holder 7402 from proceeding through gates 7494 a, 7494 b, or7494 c until the account holder 7402 has provided the account authority7412 with a “sufficient” level of entity authentication—at least to theextent required by the particular gate 7494 a,7494 b,7494 c. For reasonsthat should be readily apparent, the level of entity authenticationrequired by each gate varies depending upon what the specific resourceis that is being protected. For example, if the resource is a parkingdeck, only a minimal level of entity authentication is necessary; if theresource is a corporate checking account, stronger entity authenticationis likely required; if the resource is the control system for launchingnuclear warheads, even stronger entity authentication is required.

In some circumstances, providing a sufficient level of entityauthentication is all that is needed to obtain access to the resource.For example, gate 7494 a provides the only session authentication hurdleto account holder 7402 for accessing resource 7440 (although, of course,the amount of access provided to the account holder 7402 and the processby which the account holder 7440 is able to access the resource may befurther restricted by permissions and access rights, which are notdiscussed in detail herein). Alternatively, as illustrated by resource7450, providing a sufficient level of entity authentication to passthrough gate 7494 b enables the account holder 7402 to access resource7450 generally and to access sub-resources 7450 a,7450 b (nested withinthe confines of resource 7450) specifically. Notably, stronger entityauthentication is necessary before account holder 7402 is given accessto sub-resource 7450 c, as indicated by gate 7494 d. In anotheralternative arrangement, providing a sufficient level of entityauthentication to pass through gate 7494 c enables the account holder7402 to access not only resource 7460 but also independent resources7470,7480,7490, which are not within the protective confines of resource7460 but which allow the account holder 7402 with access therein whenthe account holder 7402 has provided sufficient entity authentication topass through gate 7494 c.

As stated previously, in some circumstances, the particular resource7440,7450,7460 is not only protected but also maintained by the accountauthority 7412 (for example, if the account authority 7412 is afinancial institution and the resource is a bank account of the accountholder 7402). In other circumstances, the particular resource7440,7450,7460 is merely protected by the account authority 7412, whichis in communication and coordination with another entity, such as aresource manager, access controller, or authorization controller (notshown), that actually maintains the resource (for example, if theaccount authority 7412 is merely an entity authentication system and theresource is a secure network server, to which access and permissions arecontrolled by a separate access control server).

The illustration of FIG. 74 is equally applicable to an EC used fortransaction authentication purposes. For example, if EC 7406 contains aspecific request for information from one of the resources7440,7450,7460 or a request for the account authority 7412 to perform aspecific action on or in one of the resources 7440,7450,7460, then theEC 7406 is used for entity authentication solely for that particularrequest; however, no on-going or session access to the particularresource 7440,7450,7460 is granted as a result.

Turning now to FIG. 75, three different examples of ECs between anaccount holder 7502 and an account authority 7512 over communicationsmedium 7508 are illustrated. In all three examples, the last EC from theaccount holder 7502 to the account authority 7512 is used for atransaction confirmation purpose.

In the first interchange, designated by EC 1A in FIG. 75, the accountholder 7502 transmits an EC, which contains a message (M1) and a digitalsignature for the message (DS(M1)). In this interchange, the accountholder 7502 provides sufficient proof of intent and Factor B or C EntityAuthentication such that the account authority 7512 requires nofollow-up EC requesting confirmation.

In the second interchange, designated by ECs 2A, 2B, and 2C and stillwith reference to FIG. 75, the account holder 7502 transmits an EC,which contains a message (M2) and a digital signature for the message(DS(M2)). In this interchange, the account authority 7512 is notsatisfied that it has received sufficient proof of the account holder'sintent as applied to the message (M2). For this reason, the accountauthority 7512 sends EC 2B to the account holder 7502; EC 2B requeststhat the account holder 7502 send a new EC with the same message (M2)and digital signature therefor (DS(M2)) but with the additionalperformance of Factor B or C Entity Authentication, an indicator (EAI)of which is included therewith as “proof” that the account holder 7502did intend to send EC 2A. As shown, the message of EC 2C is essentiallythe same as the message of original EC 2A with the addition of theEntity Authentication indicator (EAI). Such Entity Authenticationindicator (EAI), preferably, is included within the message (M2) that isdigitally signed.

In the third interchange, designated by ECs 3A, 3B, and 3C and stillwith reference to FIG. 75, the account holder 7502 transmits an EC,which contains a message (M3) and a digital signature therefor (DS(M3)).In this interchange, the account authority 7512 is not satisfied that ithas received sufficient proof of the account holder's intent as appliedto the message (M3). For this reason, in this example, the accountauthority 7512 sends EC 3B to the account holder 7502; EC 3B contains aproposed new message (M4) for review and digital signing by the accountholder 7502. Message (M4) is composed by the account authority 7512 andpreferably contains most, if not all, of the information that wascontained in message (M3). Message (M4) may also contain additionalinformation not contained in message (M3). Further, EC 3B requests that,if the account holder 7502 agrees with and accepts the contents ofmessage (M4), that the account holder 7502 modify the message (M4) in aspecified manner (indicated in EC 3B or based on a known protocol) tocreate a modified message (mod-M4) and then digitally sign the same(DS(mod-M4)). It is possible to perform Factor B or C EntityAuthentication and include an indicator (EAI) thereof within EC 3C;however, it is not required since account authority 7512 did not requestit in EC 3B.

g. Data Structure and Formats for ECs in an ABDS System

Referring now to FIG. 76, an electronic communication (EC) 7601 inaccordance with various aspects of the inventions described hereinincludes various data fields, elements, or portions, generally speaking,a message (M) 7603 and a digital signature (DS) 7605. These componentsgenerally form a data structure that may be stored, communicated, orotherwise manipulated with computing and communications apparatuses,according to the methods described herein. The EC 7601 may be includedwith, and/or form a part of, a financial transaction in accordance withISO Standard 8583, which is incorporated herein by reference, or anX9.59 transaction.

In accordance with known data communication formats and/or datastructure conventions, the EC 7601 typically includes a header portion7607, a body 7609, and a trailer portion 7611. The header portion 7607and trailer portion 7611 are conventional in nature and are provided forconventional purposes, such as identification of the EC, routing, errorcorrection, packet counting and sequencing, and other purposes, as willbe known to those skilled in the art.

According to a first arrangement of this aspect of the invention, thebody portion 7609 comprises a message 7603 and the digital signature7605 therefor (separated by a hashed line in the illustration). Themessage 7603 preferably includes an account identifier 7616 and messagecontent 7618. The message content can include various types ofinformation such as a further identifier, a command or instruction (i1)relating to the account, the public key (PuK) associated with theaccount, time/date stamp, encrypted message, and the like. The digitalsignature 7605 comprises information from the message 7603 (for example,a hash of the message, the message itself, or a compressed), signed withthe sender's private key.

According to a second arrangement, the body portion 7609 comprises theaccount identifier 7616 and a message content portion 7618, whichincorporates the digital signature 7605 (ignoring the hashed line). Theaccount identifier 7616 may be considered a separate component from themessage content 7618. Similar to the first arrangement, the digitalsignature 7605 portion of the message content 7618 comprises otherinformation from the message content 7618, signed with the sender'sprivate key.

Under either of the above arrangements, the EC 7601 includes the accountidentifier 7616 and the digital signature 7605 as significant componentsthereof.

It will be appreciated that the digital signature 7605 of anyarrangement of data elements may constitute information such as theaccount identifier, a further identifier, an instruction or commandrelating to the account, the public key (PuK) of the sender of the EC,and/or other information, depending upon the particular applicationcontemplated by the user of the invention. AS stated previously, themessage 7603 need not contain the account identifier 7616, e.g. theaccount identifier is implied or inferred, or obtained from, themessage. For example, the recipient of the EC may have already obtainedthe account identifier 7616 from a previous message from the sender ofthe EC and retransmission of the account identifier 7616 is not needed.Further, it is not necessary for the message 7603 or message content7618 to contain an instruction or command, for example, when theinstruction is implicit in the communication between the sender of theEC and the recipient thereof.

Finally, it should be noted that these electronic communication and datastructure formats of the present invention are not limited to the fileformat, structure, and contents described above. Other formats,structures, and contents can be used that include different componentsand arrangements.

h. Specific Implementations of 2-Party ABDS Systems

The preferred ABDS systems 200,300 of FIGS. 2 and 3 may be implementedin a vast number of wide-ranging business applications. Because thespecific applications are so numerous, the following specific examplesare described in detail herein only to illustrate the scope and breadthof possible implementations and are not intended to be limitations onthe type of business applications in which the ABDS systems 200,300 maybe implemented. In addition, the specific device used with eachparticular business application is chosen merely for illustrativepurposes and is not intended to imply or suggest that other devicesshown (or not shown) in any other figure cannot be used therewith. Tothe contrary, any device, regardless of form, can be used in most, ifnot all, business applications utilizing the ABDS systems 200,300 ofFIGS. 2 and 3, limited only by the available infrastructure within whichsuch device is capable of operating.

In all of the following examples, it is presumed that the account holderhas already established an ABDS account with the relevant accountauthority; thus, the account maintained by the account authority hasassociated therewith the public key that corresponds with the privatekey, which is securely protected in the device, which is in thepossession of the account holder. In all of the following examples, itis also presumed that there is no need to encrypt the contents of theparticular communications between the various entities, including theaccount holders and the account authorities; however, if any of theentities desires to protect the contents of the information containedwithin the various ECs between them for privacy, confidentiality, or anysimilar reasons, such ECs may be encrypted by the sender of theparticular EC in conventional manner, for example, using the public keyof the intended recipient(s) of the particular EC for PGP-typeencryption, using secure socket layering (SSL), or other similarencryption techniques; however, encrypting the contents of the variousECs is not necessary for the functioning of the present invention.

In addition, in many of the specific business applications describedhereinafter, the account holder is prompted or asked to perform Factor Bor Factor C Entity Authentication as part of the process of composingand transmitting an EC to the account authority. It should be understoodthat mere use of the device is sufficient for providing Factor A EntityAuthentication (since authenticating the message inherently confirmsthat the sender of the EC possessed the private key corresponding to thepublic key used successfully to authenticate the message), which, inmany circumstances, is sufficient entity authentication for the accountauthority to act upon the message or instruction (i1) contained in theEC from the account holder. Performance of Factor B and/or Factor CEntity Authentication, while not necessary for the present invention,does strengthen the entity authentication provided by the account holderand, correspondingly, increases the amount of trust the accountauthority has in the system and in the fact that it is dealing with thelegitimate account holder.

Further, the methodology by which Factor B and/or Factor C entityauthentication is managed between the account holder, the device, theaccount authority, and other entities within the ABDS systems describedherein is not specifically set forth in these implementations. It shouldbe assumed that such User or Sender Authentication is handled inconventional manner (as described above) or as described in the VSApplications.

i. Financial Institution Account

A first business application 600 implementing the two-party ABDS system200 of FIG. 2 is illustrated in FIG. 6. In this example, an accountholder 602 comprising a person possesses a device in the form of a card650, such as an IC card, credit card, or ATM card, which is capable ofbeing used at an ATM machine 660 or the like. The card 650 securelyprotects therein a private key of a public-private key pair. The ATMmachine 660 includes a display 662, a card reader 664, an alphanumerickeypad 666, and a cash dispenser 668. The card 650 is associated with adebit or credit account maintained with an account authority comprisinga financial institution 612. The account may be a checking account,savings account, money market account, credit card account, or the like,and the financial institution may be a bank, savings and loan, creditcard company, or the like. In this example, the ATM machine 660communicates electronically with the financial institution 612 over asecure, internal banking network 608.

Accounts maintained with the financial institution 612 are associatedwith account records maintained in one or more account databases,collectively referred to and illustrated in FIG. 6 by account database614. With reference to FIG. 7, each account includes a unique accountidentifier comprising an account number 716. Each account number 716identifies within the account database 614 account information 740,including customer-specific information 742 and account-specificinformation 744. In accordance with the present invention, the accountnumber 716 also identifies public key information 718, which includes atleast a public key of an account holder of the respective account. Alsoin accordance with a feature of the present invention, the accountnumber 716 identifies device profile information 770 for the device thatretains the private key corresponding with the public key associatedwith the account.

In the example of FIG. 6, the customer-specific information 742includes, for example, the name, address, social security number and/ortax-ID number of the account holder. The account-specific information744 includes, for example, the current account balance, availablecredit, closing date and balance of current statement, and associatedaccount identifiers. The public key information 718 of the account ofthe account holder 602 includes the public key corresponding to theprivate key retained within the card 650. The device profile information770 includes information specific to the card 650.

As stated previously, an EC from the account holder 602 to the financialinstitution 612 may be used for three different purposes: sessionauthentication, transaction authentication, and transactionconfirmation. In this business application, the most common type of ECis used merely for session authentication, which occurs when the accountholder 602 initially attempts to login to or otherwise access the ATMmachine 660.

Regardless of which type of EC is communicated from the account holder602 to the financial institution 612, the basic methodology forcomposing and digitally signing the message (on the account holder end)and for authenticating the message and authenticating the entity (on theaccount authority end) is essentially the same. For example, turning nowto FIG. 8, a transaction in accordance with the present invention isinitiated (Step 802) in the implementation illustrated in FIGS. 6 and 7when the account holder 602 inserts the card 650 into the card reader664 of the ATM machine 660. The insertion of the card 650 initializesthe ATM machine 660, which, using display 662, prompts (Step 804) theaccount holder 602 to perform entity authentication, such as providing aPIN, using the alphanumeric keypad 666. Once the PIN is input, anelectronic message is composed (Step 806) for sending to the financialinstitution 612.

The ATM machine 660 displays a menu of available accounts upon which theaccount holder 602 may perform an action. The available accounts arestored within memory on the card 650 and retrieved by the ATM machine660 for display to the account holder 602. Of course, if only oneaccount is available in memory on the card 650, then that account isselected by default without requiring specific selection by the accountholder 602.

Upon selection of an account, the ATM machine 660 displays a menu ofoperations that can be performed on the selected account. Suchoperations include, for example, money withdrawal, balance inquiry,statement request, money transfer, money deposit, bill payment, and thelike. Upon selection of the desired operation by the account holder 602,and after any additional information relating thereto is obtained fromthe account holder 602, such as a withdrawal or transfer amount and thelike, the ATM machine 660 composes an electronic message that includesan instruction to the financial institution 612 corresponding to thedesired operation of the account holder 602. The electronic message alsoincludes the account number 716 corresponding to the account selected bythe account holder 602.

The message then is transmitted (Step 808) to the card 650 for digitalsigning by the account holder 602. In this regard, upon receipt of datarepresenting the message, the card 650 originates (Step 810) a digitalsignature for the message by first calculating a hash value for the dataand then encrypting the hash value using the private key retained withinthe card 650. The card 650 then outputs (Step 812) the digital signatureto the ATM machine 660, which then transmits (Step 814) the message andthe digital signature therefor in an EC to the financial institution612.

With reference to FIG. 9, the EC is received (Step 902) by the financialinstitution 612 from the ATM machine 660. The financial institution 612then retrieves (Step 904) from the account database 614 the public keythat is identified by the account number 716. Using this public key, thefinancial institution 612 attempts to authenticate (Step 906) themessage. If the message does not authenticate (in Step 908) using thepublic key, then the financial institution 612 responds (Step 910) witha rejection of the message (i.e., refusal to grant access to the accountor to perform the requested action). If the message authenticates (Step908), then the financial institution 612 concludes that the message, infact, came from the person possessing the correct card 650 associatedwith the identified account number 716—(i.e., Factor A EntityAuthentication is obtained). The financial institution 612 thendetermines (Step 912) whether or not the Factor B entity authenticationinformation or status (e.g., PIN) provided is sufficient for furtherprocessing of the specific message. If not, then the financialinstitution 612 responds (Step 910) with a rejection of the message(i.e., refusal to grant access to the account or to perform therequested action). If the entity authentication provided is sufficient(in Step 912), then the financial institution 612 further processes(Step 914) the message.

In this case, further processing (Step 914) of the message includesexecuting the instruction of the message, if possible, and updating theaccount based on the executed instruction. If it is not possible toexecute the instruction, then the financial institution 612 responds(Step 910) with a rejection of the message. For example, if the accountholder 602 instructs the financial institution 612 to provide an accountbalance, then the financial institution 612 transmits the accountbalance to the ATM machine 660 for presentation to the account holder602. If the account holder 602 instructs the financial institution 612to withdraw money from the account, then the financial institution 612first confirms that the funds are available and, if so, sends anauthorization to the ATM machine 660 to dispense the requested amount offunds (up to the limit allowed and/or available on the particularaccount) to the account holder 602 and updates the account record toreflect the withdrawal. If the account holder 602 instructs thefinancial institution 612 to transfer funds to another account, then thefinancial institution 612 first confirms that the funds are availableand, if so, initiates the electronic fund transfer to the other accountand updates the account records accordingly. If the account holder 602instructs the financial institution 612 to receive a payment on a billowed to the financial institution 612, such as a credit line payment,credit card payment, mortgage payment, or the like, then the financialinstitution 612 first confirms that the funds are available and, if so,initiates transfer from the account and updates the account recordsaccordingly.

As will be appreciated by those skilled in the art, if the accountholder 602 requests an “unusual” transaction, such as the withdrawal ortransfer of a large amount of money or closure of the account, thefinancial institution 612 may request that the account holder 602digitally sign an EC for transaction confirmation purposes for thespecified request. The financial institution 612 may also require thatthe account holder 602 provide additional entity authenticationinformation or status prior to the digital signature being generated bythe card 650. The ATM machine 660 may be used to advantage to sequencethe events properly so that the account holder 602 first sees theproposed confirmation message displayed on the display 662 of the ATMmachine 660, then is prompted to input a Secret or biometric value,after which the ATM machine 660 provides the confirmation message to thecard 650 for digital signature. The remaining method of generating andprocessing such transaction confirmation EC is similar to that describedabove for the session authentication.

ii. Brokerage Account

A second business application 1000 implementing the two-party ABDSsystem 200 of FIG. 2 is illustrated in FIG. 10. In this example, anaccount holder 1002 comprising a person possesses a device in the formof a personal digital assistant (PDA) 1050. The PDA 1050 securelyprotects therein a private key of a public-private key pair. The PDA1050 includes an interactive display screen 1052 and user input keys1056. Further, the PDA 1050 has been suitably equipped with a wirelessmodem for digital communications over a wireless communications network1008. The PDA 1050 is associated with a brokerage trading, assetmanagement, and credit account maintained with an account authorityrepresented by a brokerage firm 1012, which is licensed to buy and sellsecurities on behalf of the account holder 1002 and which is equipped toreceived wireless communications over network 1008.

Accounts maintained with the brokerage firm 1012 are associated withaccount records maintained in one or more account databases,collectively referred to and illustrated in FIG. 10 by account database1014. With reference to FIG. 11, each account includes a unique accountidentifier comprising an account number 1116. Each account number 1116identifies within the account database 1014 account information 1140,including customer-specific information 1142 and account-specificinformation 1144. In accordance with the present invention, the accountnumber 1116 also identifies public key information 1118, which includesat least a public key of an account holder of the respective account.Also in accordance with a feature of the present invention, the accountnumber 1116 identifies device profile information 1170 for the devicethat retains the private key corresponding with the public keyassociated with the account.

In the example of FIG. 10, the customer-specific information 1142includes, for example, the name, address, social security number and/ortax-ID number of the account holder. The account-specific information1144 includes, for example, the account status, account balance,available credit, if any, asset holdings, pending transactions, capitalgains for the year, associated account identifiers, and the like. Thepublic key information 1118 of the account of the account holder 1002includes the public key corresponding to the private key retained withinthe PDA 1050. The device profile information 1170 includes informationspecific to the PDA 1050.

As stated previously, an EC from the account holder 1002 to thebrokerage firm 1012 may be used for three different purposes: sessionauthentication, transaction authentication, and transactionconfirmation. In this business application, an EC used for sessionauthentication typically occurs when the account holder 1002 initiallyattempts to login to or otherwise access the online site of thebrokerage firm 1012. Transaction confirmation occurs in this businessapplication when, for example, the account holder 1002 specificallyrequests the brokerage firm 1012 to buy or sell a specific security—inwhich case the brokerage firm 1012 requires the account holder 1002 toconfirm such a request by digitally signing the request with the PDA1050 (and, preferably, with reentry of a Secret or biometric value).

Regardless of which type of EC is communicated from the account holder1002 to the brokerage firm 1012, the basic methodology for composing anddigitally signing the message (on the account holder end) and forauthenticating the message and authenticating the entity (on the accountauthority end) is essentially the same. For example, turning now to FIG.12, a transaction is initiated (Step 1202) when the account holder 1002first establishes a wireless connection to the online site of thebrokerage firm 1012 or, after such connection has already beenestablished, when the account holder 1002 requests information regardinghis account or requests that the brokerage firm 1012 perform an actionwith regard to the account. Next, the online site causes the PDA 1050 toprompt (Step 1204) the account holder 1002 to provide Factor B entityauthentication information, such as a PIN, if necessary, using theinteractive display 1052.

Once the PIN is input, an electronic message is composed (Step 1206) forsending to the brokerage firm 1012. For initial login, the message issimply the relevant account number. For other transactions, the messageincludes an instruction (i1) from the account holder 1002 to thebrokerage firm 1012. For initial login, the PDA 1050 displays a menu ofavailable accounts. Such accounts are displayed in response tocommunications received from the brokerage firm 1012 or from softwarepre-installed on the PDA 1050 for this purpose. Preferably, theavailable accounts are stored within a memory on the PDA 1050 andpresented on display 1052 to the account holder 1002 for selection. Ofcourse, if only one account is available in memory on the PDA 1050, thenthat account is selected by default without requiring specific selectionby the account holder 1002. For post-login transactions, the PDA 1050displays a menu of operations that can be performed on the selectedaccount. Again, this menu of options may be preprogrammed into the PDA1050 or downloaded from the brokerage firm 1012 when the electronicconnection is made between the PDA 1050 and the brokerage firm 1012.Such operations include, for example, a request for an account status,an account balance, available credit, a list of current asset holdings,or a list of pending transactions, or a request to purchase or sell asecurity. Upon selection of the desired operation by the account holder1002, and after any additional information relating thereto is obtainedfrom the account holder 1002, such as a purchase or sale amount andselection of a particular security, the PDA 1050 composes an electronicmessage that includes an instruction to the brokerage firm 1012corresponding to the desired operation of the account holder 1002. Theelectronic message also includes the account number 1116 correspondingto the account selected by the account holder 1002.

The PDA 1050 then originates (Step 1208) a digital signature for themessage by first calculating a hash value for the data and thenencrypting the hash value using the private key retained within the PDA1050. The PDA 1050 then outputs (Step 1210) the message and digitalsignature therefor to the wireless modem of the PDA 1050, which thentransmits (Step 1212) the message and the digital signature in an EC tothe brokerage firm 1012.

With reference to FIG. 13, the EC is received (Step 1302) by brokeragefirm 1012 from the PDA 1050. The brokerage firm 1012 then retrieves(Step 1304) from the account database 1014 the public key that isidentified by the account number 1116. Using this public key, thebrokerage firm 1012 attempts to authenticate (Step 1306) the message. Ifthe message does not authenticate (in Step 1308) using the public key,then the brokerage firm 1012 responds (Step 1310) with a rejection ofthe message (i.e., refusal to grant access to the account or to performthe requested action). If the message authenticates (Step 1308), thenthe brokerage firm 1012 concludes that the message, in fact, came fromthe person possessing the correct PDA 1050 associated with theidentified account number 1116—(i.e., Factor A Entity Authentication isobtained). The brokerage firm 1012 then determines (Step 1312) whetheror not the Factor B entity authentication (e.g., PIN) provided issufficient for further processing of the specific message. If not, thenthe brokerage firm 1012 responds (Step 1310) with a rejection of themessage (e.g., refusal to grant access to the account or perform therequested action). If the entity authentication is sufficient (in Step1312), then the brokerage firm 1012 further processes (Step 1314) themessage.

In the present example, further processing (Step 1314) of the messageafter initial session authentication includes accessing the relevantportion(s) of the account record and displaying the welcome web sitescreen on the PDA personalized to the account holder 1002. Furtherprocessing of the message after initial login includes executing theinstruction (if possible) and updating the account record based on theexecuted instruction. If it is not possible to execute the instruction,then the brokerage firm 1012 responds (Step 1310) with a rejection ofthe message. For example, if the account holder 1002 instructs thebrokerage firm 1012 to provide an account status, an account balance,amount of available credit, a list of current asset holdings, a list ofpending transactions, or information regarding a particular security,then the brokerage firm 1012 obtains the requested information andtransmits it to the PDA 1050 over the wireless communication network1008 for display to the account holder 1002 on the display screen 1052of the PDA 1050. If the account holder 1002 instructs the brokerage firm1012 to purchase a specified number of shares of a particular securityat a specified price, then the brokerage firm 1012 first confirms thatthe funds for the purchase are available and, if so, places anappropriate “buy” order in the securities market in conventional manner.If and when the purchase of the securities closes, the account recordsare updated accordingly (i.e., the shares purchased are added to thelist of asset holdings and the purchase price (plus commissions) isdebited or charged to the account). If the account holder 1002 instructsthe brokerage firm 1012 to sell a specified number of shares of aparticular security at a specified price, then the brokerage firm 1012first confirms that the number of shares of the particular security areowned by the account holder 1002 and capable of being sold and, if so,places an appropriate “sell” order in the securities market inconventional manner. If and when the sale of the securities closes, theaccount records are updated accordingly (i.e., the shares sold areremoved from the list of asset holdings and the sales price (minuscommissions) is credited to the account). For instructions to buy orsell securities, it is preferable for the brokerage firm 1012 to obtaina confirmation transaction, as described above, from the account holder1002 before executing the requested instruction.

iii. Bill Payment Services Account

A third business application 1400 implementing the two-party ABDS system200 of FIG. 2 is illustrated in FIG. 14. In this example, an accountholder 1402 comprising a person possesses a device in the form of a cellphone 1450. The cell phone 1450 securely protects therein a private keyof a public-private key pair. The cell phone 1450 includes a displayscreen 1452 and a number pad 1456. Further, the cell phone 1450 has beensuitably equipped for wireless voice and data communications over awireless communications network 1408. The cell phone 1450 is associatedwith a bill payment account (which may include one or more checkingaccounts, credit card accounts, etc.) maintained with an accountauthority represented by a bill payment service 1412, which isauthorized to pay bills to third parties on behalf of the account holder1402 and which has an automated call center equipped to receivedwireless voice and data communications over network 1408.

Various payees 1410 a,1410 b to which the account holder 1402 owes moneyare also illustrated in FIG. 14. Preferably, the payees 1410 a,1410 bare third parties to which the account holder 1402 is obligated to payperiodically and on a recurring basis. Payees 1410 a,1410 b may be, forexample, mortgage companies, utility companies, credit card companies,retail merchants, department stores, doctors' offices, and other goodsand/or service providers that typically bill on a monthly basis forcharges incurred by the account holder 1402 during the previous month.In this particular business application 1400, it is contemplated thatthe account holder 1402 will provide the bill payment service 1412 withthe billing information, such as statement date, bill due date, and billamount owed to each payee 1410 a,1410 b. In an alternative embodiment,the payees 1410 a,1410 b can be authorized by the account holder 1402 toprovide billing information directly to the bill payment service 1412.Such billing information may be transmitted by any suitable means,including via dedicated payment network 1411.

Accounts maintained with the bill payment service 1412 are associatedwith account records maintained in one or more account databases,collectively referred to and illustrated in FIG. 14 by account database1414. With reference to FIG. 15, each account includes a unique accountidentifier comprising an account number 1516. Each account number 1516identifies within the account database 1414 account information 1540,including customer-specific information 1542 and account-specificinformation 1544. In accordance with the present invention, the accountnumber 1516 also identifies public key information 1518, which includesat least a public key of an account holder of the respective account.Also in accordance with a feature of the present invention, the accountnumber 1516 identifies device profile information 1570 for the devicethat retains the private key corresponding with the public keyassociated with the account.

In the example of FIG. 14, the customer-specific information 1542includes, for example, the name, address, social security number and/ortax-ID number of the account holder. The account-specific information1544 includes, for example, a list of available payment accounts,account balances for each such payment account, authorized credit cardnumber(s), available credit, if any, with the bill payment service 1412,current statement, current status report, list of payees registered bythe account holder 1402, customer account number and billing address foreach registered payee, and current billing information for eachregistered payee (if available), and the like. The public keyinformation 1518 of the account of the account holder 1402 includes thepublic key corresponding to the private key retained within the cellphone 1450. The device profile information 1570 includes informationspecific to the cell phone 1450.

As stated previously, an EC from the account holder 1402 to the billpayment service 1412 may be used for three different purposes: sessionauthentication, transaction authentication, and transactionconfirmation. In this business application, an EC used for sessionauthentication typically occurs when the account holder 1402 initiallyattempts to login to or otherwise access the automated call center ofthe bill payment service 1412. Transaction confirmation occurs in thisbusiness application when, for example, the account holder 1402specifically requests the bill payment service 1412 to pay a certainbill—in which case the bill payment service 1412 requires the accountholder 1402 to confirm such a request by digitally signing the requestwith the cell phone 1450 (and, potentially, providing additional entityauthentication information or status).

Regardless of which type of EC is communicated from the account holder1402 to the bill payment service 1412, the basic methodology forcomposing and digitally signing the message (on the account holder end)and for authenticating the message and authenticating the entity (on theaccount authority end) is essentially the same. For example, turning nowto FIG. 16, a transaction is initiated (Step 1602) when the accountholder 1402 uses the cell phone 1450 to establish a wireless phone callto the automated call center of the bill payment service 1412 or, aftersuch connection has already been established, when the account holder1402 requests information regarding his account or requests that thebill payment service 1412 perform an action with regard to the account.For initial login or for confirmation of a specifically requestedtransaction, the account holder 1402 next inputs (Step 1604) Factor Bentity authentication information, such as a PIN, using the number pad1456 of the cell phone 1450.

Once the PIN is input, an electronic message is composed (Step 1606) forsending to the bill payment service 1412. The first message (containingonly the account number) is composed by the account holder 1402depressing keys on the number pad 1456 of the cell phone 1450 followedby a designated key (or series of keys), such as the “#” key, whichindicates that the first message is complete. Preferably, depressing thedesignated key (or series of keys) not only notifies the cell phone 1450that the first message is complete, but also causes the cell phone 1450to originate (Step 1608) a digital signature for this first message.Next, the cell phone 1450 transmits (Step 1610) the message and digitalsignature in an EC to the bill payment service 1412 over the wirelesscommunications network 1408.

Now referring to FIG. 17, this initial EC is received (Step 1702) by thebill payment service 1412 from the cell phone 1450. The bill paymentservice 1412 retrieves (Step 1704) from the account database 1414 thepublic key that is identified by the account number 1516. Using thispublic key, the bill payment service 1412 attempts to authenticate (Step1706) the message. If the message does not authenticate (in Step 1708),then the bill payment service 1412 responds (Step 1710) to the sender ofthe EC with a rejection of the EC. Such a response may indicate thereason for the rejection, if desired by the bill payment service 1412.On the other hand, if the message authenticates (in Step 1708), the billpayment service 1412 concludes that the message, in fact, came from theperson possessing the correct cell phone 1450 associated with theidentified account number 1516—(i.e., Factor A Entity Authentication isobtained). The bill payment service 1412 then determines (Step 1712)whether or not the Factor B entity authentication (e.g., PIN) providedis sufficient for further processing of the specific message. If not,then the bill payment service 1412 responds (Step 1710) with a rejectionof the message (e.g., refusal to grant access to the account or performthe requested action) and, again, such response may indicate the reasonfor the rejection. If the entity authentication (in Step 1712) issufficient, then the bill payment service 1412 further processes (Step1714) the message.

In the present example, further processing (Step 1714) of the message,which, in response to the message containing only the account number1516, is an automated telephonic response to the account holder 1402with a menu of options that can be performed on the now-identifiedaccount 1516.

Referring back to FIG. 16, the presentation of the automated telephonicresponse initiates the process of generating (Step 1612) a bill paymentmessage. In this specific illustration, the automated telephonicresponse presents the account holder 1402 with the following: “Press 1to pay a bill, Press 2 to schedule a payment due date for a new bill fora registered payee, Press 3 to register a new payee.” The account holder1402 is then lead through a hierarchy of menu options over the cellphone 1450 until a complete bill payment transaction can be formulatedby the bill payment service 1412. Preferably, no digital signatures needto be generated or sent during the menu selection/message generationprocess. Upon completion of the menu selections, the bill paymentservice 1412 audibly presents the account holder 1402 with a proposedpayment transaction. The number (#) key is used in the following examplemerely for illustrative purposes; however, it should be understood thatany other key, sequence of keys, or operation of the phone couldalternatively be used. For example, if the account holder 1402 initiallyselected option 1 (to pay a bill), a proposed instruction could be: “Youhave requested that we pay [Payee 1] in the amount of $51.00 on Nov. 4,1998, for a bill dated Oct. 22, 1998, with reference to [Payee 1]customer account number 012-00009-003, using your payment account #01-009000-010. If this is correct, please depress the number (#) key onyour phone.” If the account holder 1402 had initially selected option 2(to input a new bill for a registered payee), a proposed instructioncould be: “You have requested that we schedule a payment due to [Payee1] in the amount of $51.00 due on or before Nov. 22, 1998, for a billdated Oct. 22, 1998, with reference to [Payee 1] customer account number012-00009-003. If this is correct, please depress the number (#) key onyour phone.” If the account holder 1402 had initially selected option 3(to register a new payee), a proposed instruction could be: “You haverequested that we add [Payee 1] to your list of registered payees. Youhave indicated that your customer account number with [Payee 1] is012-00009-003 and that [Payee 1]'s billing address is 123 Main St,AnyTown, AnyState 01234. If this is correct, please depress the number(#) key on your phone.” If the account holder 1402 presses any key otherthan the number (#) key after this audio prompt, the proposedinstruction is not accepted (in Step 1614) and the process of composinga message (Step 1612) through selection of menu items continues. On theother hand, if the account holder 1402 presses the number (#) key on thecell phone 1450 after one of the above audio prompts, the proposedpayment transaction is accepted (Step 1614) and the cell phone 1450originates (Step 1616) a digital signature for the proposed paymenttransaction. The message that is digitally signed can either be thedigital audio file of the proposed payment transaction as accepted,which can be temporarily stored in RAM on the cell phone 1450, or thebill payment service 1412 can transmit a message to the cell phone 1450for digital signature in response to the number (#) key being depressedin response to the last menu selection. In either case, the cell phone1450 then transmits (Step 1618) the message and digital signature in anEC to the bill payment service 1412 over the wireless communicationsnetwork 1408.

As described immediately above, the message that is digitally signed canbe a digital audio file of the proposed instruction as accepted by theaccount holder 1402 by pressing the number (#) key. In an alternateembodiment of this aspect of the invention, rather than pressing thenumber (#) key to accept the proposed instruction, the account holder1402 verbally accepts the proposed instruction or verbally composes aninstruction, which is temporarily stored in RAM on the cell phone 1450as a digital file and for which a digital signature is then originatedby the cell phone 1450.

Referring again to FIG. 17, the steps performed by the bill paymentservice 1412 in response to a payment transaction EC received from theaccount holder 1402 are essentially the same as those performed inresponse to an account-only EC. The main difference, however, is in Step1714, during which the bill payment service 1412 further processes thepayment transaction message by performing or attempting to perform thepayment instruction. Performing the instruction typically involvesaccessing the relevant portion(s) of the account record, executing theinstruction (if possible), and updating the account record based on theexecuted instruction. If it is not possible to execute the instruction,then the bill payment service 1412 responds (Step 1710) with a rejectionof the message. For example, if the account holder 1402 instructs thebill payment service 1412 to pay a bill, then the bill payment service1412 schedules payment to be made (by mail or electronic transferthrough payment network 1411) on the scheduled payment date and confirmsthat the funds are currently available from the payment account 1516specified by the account holder 1402. Either the funds may be set asideat that time or the bill payment service 1412 may re-confirmavailability of funds from the specified payment account 1516 on thescheduled payment date. On the scheduled payment date, if the funds areavailable, then the bill payment services 1412 mails or electronicallytransfers the funds to the designated payee and updates the accountrecords accordingly. If the account holder 1402 merely instructs thebill payment service 1412 to schedule a new bill that is due to be paidto a registered payee, then the bill payment service 1412 merely updatesthe account records accordingly. Likewise, if the account holder 1402merely instructs the bill payment service 1412 to add a new payee to theaccount holder's list of registered payees, then the bill paymentservice 1412 merely updates the account records accordingly.

iv. Credit Bureau Account

A fourth business application 1800 implementing the two-party ABDSsystem 200 of FIG. 2 is illustrated in FIG. 18. In this example, anaccount holder 1802 comprising a person possesses a device in the formof a dongle 1850 connected via cable 1865 into a suitable port (USB,serial, parallel, etc.) of a personal computer 1860. The dongle 1850securely protects therein a private key of a public-private key pair.The personal computer 1860 is conventional in that it includes a monitor1862, a keyboard 1864, and a mouse 1866. The dongle 1850 is associated,among other accounts, with a personal credit report account maintainedby an account authority represented by a credit bureau 1812. Thecomputer 1860 has suitable web browser software installed thereon toenable it to communicate over the Internet 1808, in conventional manner,such as via a modem, LAN line, etc., with a secure web site hosted bycredit bureau 1812.

Accounts maintained with the credit bureau 1812 are associated withaccount records maintained in one or more account databases,collectively referred to and illustrated in FIG. 18 by account database1814. With reference to FIG. 19, each account includes a unique accountidentifier comprising an account number 1916. Each account number 1916identifies within the account database 1814 account information 1940,including customer-specific information 1942 and account-specificinformation 1944. In accordance with the present invention, the accountnumber 1916 also identifies public key information 1918, which includesat least a public key of an account holder of the respective account.Also in accordance with a feature of the present invention, the accountnumber 1916 identifies device profile information 1970 for the devicethat retains the private key corresponding with the public keyassociated with the account.

In the example of FIG. 18, the customer-specific information 1942includes, for example, the name, address, social security number and/ortax-ID number of the account holder. The account-specific information1944 includes, for example, a list of accounts, payment history on eachaccount, past due amount on each account, if any, total debt, creditscore, overall credit status report, and the like. The public keyinformation 1918 of the account of the account holder 1802 includes thepublic key corresponding to the private key retained within the dongle1850. The device profile information 1970 includes information specificto the dongle 1850.

As stated previously, an EC from the account holder 1802 to the creditbureau 1812 may be used for three different purposes: sessionauthentication, transaction authentication, and transactionconfirmation. For example, a common type of session authenticationoccurs in this business application when the account holder 1802initially attempts to login to or otherwise access the secure web sitemaintained by the credit bureau 1812. A further type of session entityauthentication occurs when the account holder 1802 requests access tospecific records or pieces of information that are very sensitive,secure, confidential, or private for the account holder 1802, in whichcase, the credit bureau 1812 may require a stronger level of entityauthentication than is required merely to access the secure web site.Transaction confirmation is applicable in this business applicationwhen, for example, the account holder 1802 requests the credit bureau1812 to add or change information in the account maintained by thecredit bureau 1812, in which case the credit bureau 1812 requires theaccount holder 1802 to confirm such a transaction by digitally signingthe request with the dongle 1850.

Regardless of which type of EC is communicated from the account holder1802 to the credit bureau 1812, the basic methodology for composing anddigitally signing the message (on the account holder end) and forauthenticating the message and authenticating the entity (on the accountauthority end) is essentially the same. For example, turning now to FIG.20, a transaction is initiated (Step 2002) when the account holder 1802first accesses the secure web site of the credit bureau 1812 over theInternet 1808 using computer 1860 or, after such access has already beenestablished, when the account holder 1802 requests access to specificinformation or requests that the credit bureau 1812 perform an action onthe account. Next, the web site causes the computer 1860 to prompt (Step2004) the account holder 1802 to input Factor B entity authenticationinformation, such as a PIN, using the keyboard 1864.

Once the PIN is input, an electronic message is composed (Step 2006) forsending to the credit bureau 1812. For initial login, the message issimply the relevant account number. For subsequent transactions, themessage includes an instruction (i1) from the account holder 1802 to thecredit bureau 1812. For initial login, the computer 1860 displays onmonitor 1862 a data input screen that contains an account number dataentry field. For subsequent transactions, the computer 1860 displays onmonitor 1862 a data input screen that contains additional data entry or“product” selection buttons with which the account holder 1802 is ableto select the type of transaction he would like to initiate, such as,“provide credit report,” “provide credit score,” “provide total debt,”“submit additional information,” or “report error.” Once any necessarydata fields have been filled in and an instruction selected (ifapplicable), the account holder 1802 activates the “digital signature”button also displayed on the data entry screen using the mouse 1866.

Selecting this button causes the computer 1860 to bundle the dataentered into the data entry fields and pull down menus into a singlemessage. This message then is transmitted (Step 2008) via cable 1865from the computer 1860 to the dongle 1850 for digital signing by theaccount holder 1802. In this regard, upon receipt of data representingthe message, the dongle 1850 originates (Step 2010) a digital signaturefor the message by first calculating a hash value for the data and thenencrypting the hash value using the private key retained within thedongle 1850. The dongle 1850 then outputs (Step 2012) the digitalsignature, which is received by the computer 1860. The computer 1860then transmits (Step 2014) the message and the digital signaturetherefor in an EC to the credit bureau 1812.

With reference to FIG. 21, the EC is received (Step 2102) by the creditbureau 1812 from the computer 1860. The credit bureau 1812 thenretrieves (Step 2104) from the account database 1814 the public key thatis identified by the account number 1916 (or other unique identifiersuch as name or social security number). Using this public key, thecredit bureau 1812 attempts to authenticate (Step 2106) the message. Ifthe message does not authenticate (in Step 2108) using the public key,then the credit bureau 1812 responds (Step 2110) with a rejection of themessage (i.e., refusal to grant access to the account or to perform therequested action). If the message authenticates (Step 2108), then thecredit bureau 1812 concludes that the message in fact, came from theperson possessing the correct dongle 1850 associated with the identifiedaccount number 1916—(i.e., Factor A Entity Authentication is obtained).The credit bureau 1812 then determines (Step 2112) whether or not theFactor B entity authentication (e.g., PIN) provided is sufficient forfurther processing of the specific message. If not, then the creditbureau 1812 responds (Step 2110) with a rejection of the message (e.g.,refusal to grant access to the account or to perform the request actionon the account) and, again, such response may indicate the reason forthe rejection. If the entity authentication is sufficient (in Step2112), then the credit bureau 1812 further processes (Step 2114) themessage.

In the present example, further processing (Step 2114) of the messageafter initial session authentication includes accessing the relevantportion(s) of the account record and displaying the welcome web sitescreen on the computer 1860 personalized to the account holder 1802.Further processing of the message after initial login includes accessingthe relevant portion(s) of the account record, executing the instruction(if possible), and updating the account record based on the executedinstruction. If it is not possible to execute the instruction, then thecredit bureau 1812 responds (Step 2110) with a rejection of the message.For example, if the account holder 1802 instructs the credit bureau 1812to provide a full credit report, a credit score, or a total debtcalculation, then the credit bureau 1812 accesses the account database1814 to obtain the relevant information, which is then transmitted tothe computer 1860 for display on monitor 1862 to the account holder1802. If the account holder 1802 instructs the credit bureau 1812 thatit desires to submit additional information for inclusion in the accountdatabase 1814, then the credit bureau 1812 presents a new data entrypage into which the account holder 1802 can submit new information. Thisnew data entry page constitutes a new message that is digitally signedusing the dongle 1850 and transmitted to the credit bureau 1812 in thesame manner described above. Likewise, if the account holder 1802instructs the credit bureau 1812 that it desires to report an error inthe credit report or account database, then the credit bureau 1812presents a new data entry page to the account holder 1802 into which theaccount holder 1802 can report the alleged error. This new data entrypage constitutes a new message that is digitally signed using the dongle1850 and transmitted to the credit bureau 1812 in the same mannerdescribed above. Once the credit bureau 1812 receives new information oran alleged error notice from the account holder 1802, then it initiatesan investigation into the matter. If the information appears to beaccurate, then the appropriate record(s) in the account database 1814 isupdated accordingly. For some of the above instructions, it ispreferably for the credit bureau 1812 to obtain a confirmationtransaction, as described above, from the account holder 1802 beforeexecuting the requested instruction.

v. Patient/Personal Medical Records Account

A fifth business application 2200 implementing the two-party ABDS system200 of FIG. 2 is illustrated in FIG. 22. In this example, an accountholder comprising a patient 2202 possesses a device in the form of acard 2250, such as an IC card. The card 2250 securely protects therein aprivate key of a public-private key pair and is capable of being used ina card reader 2252. The card reader 2252 includes an alphanumeric keypad2256, a display 2254, and a thumbprint reader 2258. The card reader 2252is connected via cable 2265 into a suitable port (USB, serial, parallel,etc.) of a personal computer 2260. The personal computer 2260 isconventional in that it includes a monitor 2262, a keyboard 2264, and amouse 2266. As will be appreciated by those skilled in the art, usingthe display 2254 of the card reader 2252 for displaying messages to bedigitally signed and using the keypad 2256 and thumbprint reader 2258 onthe card reader 2252 for receiving entity authentication informationfrom the patient 2202 provides greater security and less potential forfraud than if the same information was displayed and input on thecomputer 2260 using monitor 2262 and keyboard 2264.

The card 2250 is associated, among other accounts, with a medicalrecords' account associated specifically with the patient 2202 andmaintained by an account authority represented by a medical recordsaccess manager 2212. The computer 2260 is connected directly with themedical records access manager 2212 and has custom software installedtherein for enabling patients registered with the medical records accessmanager 2212 to access and view selected portions of their personalmedical records as maintained by the medical records access manager2212.

Accounts maintained with the medical records access manager 2212 areassociated with account records maintained in one or more accountdatabases, collectively referred to and illustrated in FIG. 22 byaccount database 2214. With reference to FIG. 23, each account includesa unique account identifier comprising an account number 2316. Eachaccount number 2316 identifies within the account database 2214 accountinformation 2340, including customer-specific information 2342 andaccount-specific information 2344. In accordance with the presentinvention, the account number 2316 also identifies public keyinformation 2318, which includes at least a public key of an accountholder of the respective account. Also in accordance with a feature ofthe present invention, the account number 2316 identifies device profileinformation 2370 for the device that retains the private keycorresponding with the public key associated with the account.

In the example of FIG. 22, the customer-specific information 2342illustrated in FIG. 23 includes, for example, the name, address, socialsecurity number and/or tax-ID number of the patient 2202. Theaccount-specific information 2344 includes, for example, current list ofdoctors, current insurance information, medical profile and history,known allergies, major medical conditions, organ donor information, andthe like. The public key information 2318 of the account of the patient2202 includes the public key corresponding to the private key retainedwithin the card 2250. The device profile information 2370 includesinformation specific to the card 2250.

As stated previously, an EC from the patient 2202 to the medical recordsaccess manager 2212 may be used for three different purposes: sessionauthentication, transaction authentication, and transactionconfirmation. For example, a common type of session authenticationoccurs in this business application when the patient 2202 initiallyattempts to login to or otherwise access the medical record accesssoftware maintained on the computer 2260. Further session authenticationoccurs when the patient 2202 requests access to specific records orpieces of information that are very sensitive, secure, confidential, orprivate for the patient 2202, in which case, the medical records accessmanager 2212 may require a stronger level of entity authentication (e.g.Factor C using the thumbprint reader 2258) than is required merely toaccess the relevant software. Transaction confirmation is applicable inthis business application (during either of the sessions describedabove) when, for example, the patient 2202 requests the medical recordsaccess manager 2212 to perform an action upon the patient's informationcontained within the medical records database (e.g., updating, adding,deleting, or forwarding such information) and the medical records accessmanager 2212 requires the patient 2202 to confirm such a request bydigitally signing the request with the card 2250 (and, potentially, alsoproviding additional Factor B or C entity authentication information orstatus).

Regardless of which type of EC is communicated from the patient 2202 tothe medical records access manager 2212, the basic methodology forcomposing and digitally signing the message (on the patient end) and forauthenticating the message and authenticating the entity (on the medicalrecords access manager end) is essentially the same. For example,turning now to FIG. 24, an EC in accordance with the present inventionis initiated (Step 2402) when the patient 2202 first attempts to loginto the computer 2260 for accessing the medical records' software or,after such login has already been completed successfully, when thepatient 2202 requests sensitive patient information or requests that themedical records access manager 2212 perform an action with regard to thepatient's account. In either case, the computer 2260 prompts (Step 2404)the patient 2202 to provide the card 2250 to the card reader 2252 (e.g.,by inserting the card 2250 if the reader 2252 is a “contact” type readeror by bringing the card 2250 into close proximity to the reader 2252 ifit is a “contactless” type reader) if it has not already been soprovided. The computer 2260 then prompts (Step 2406) the patient 2202 toprovide Factor B and/or C entity authentication information using thealphanumeric keypad 2256 and/or the thumbprint reader 2258. Once suchentity authentication information is provided, an electronic message iscomposed (Step 2408) for sending to the medical records access manager2212. In this case, with an initial EC that merely requests access tothe system, the message is merely the account number 2316 associatedwith the account maintained by the medical records access manager 2212.Preferably, the reader 2252 displays on display 2254 a menu of availableaccounts from which the patient 2202 can select. Preferably, suchavailable accounts are stored within memory on the card 2250 andretrieved by the reader 2252 for selection by the patient 2202. Ofcourse, if only one account is available in memory on the card 2250,then that account is selected by default without requiring specificselection by the patient 2202. For subsequent transactions, the patient2202 is able to select (on the computer 2260) what information she wantsto view or what action she wants the medical records access manager 2212to perform.

In either case, once the computer 2260 has composed the message, it istransmitted (Step 2410) to the card reader 2252 for display on display2254 and for forwarding to the card 2250 for digital signing by thepatient 2202: In this regard, upon receipt of data representing themessage, the card 2250 originates (Step 2412) a digital signature forthe message by first calculating a hash value for the data and thenencrypting the hash value using the private key retained within the card2250. The card 2250 then outputs (Step 2414) the digital signature,which is received initially by the reader 2252. The reader 2252 thentransmits (Step 2416) the digital signature along with the message as anEC to the computer 2260, which forwards the same to the medical recordsaccess manager 2212 for authentication.

With reference to FIG. 25, the EC is received (Step 2502) by the medicalrecords access manager 2212 from the computer 2260. The medical recordsaccess manager 2212 then retrieves (Step 2504) from the account database2214 the public key that is identified by the account number 2316. Usingthis public key, the medical records access manager 2212 attempts toauthenticate (Step 2506) the message. If the message does notauthenticate (in Step 2508), then the medical records access manager2212 responds (Step 2510) with a rejection of the message (i.e., refusalto grant access to the web site or refusal to perform the requestedaction). Such a response may indicate the reason for the rejection. Ifthe message does authenticate (in Step 2508), then the medical recordsaccess manager 2212 concludes that the message, in fact, came from theperson possessing the correct card 2250 associated with the identifiedaccount number 2316—(i.e., Factor A Entity Authentication is obtained).The medical records access manager 2212 then determines (Step 2512)whether or not the Factor B and/or C entity authentication (e.g., PINand/or thumbprint) provided is sufficient for further processing of thespecific message. If not, then the medical records access manager 2212responds (Step 2510) with a rejection of the message and, again, suchresponse may indicate the reason for the rejection. If the entityauthentication is sufficient (in Step 2512), then the medical recordsaccess manager 2212 further processes (Step 2514) the message.

For initial login, further processing of the message merely meansproviding the patient 2202 with access to the records access program onthe computer 2260 and with rights to view private but not sensitiveinformation pertaining to the patient 2202 as maintained in the database2214 and displayed in response to suitable inquiries using the customsoftware on the computer 2260. If the message is an request by thepatient 2202 for access to sensitive information pertaining to thepatient 2202, the medical records access manager 2212 may requirestronger entity authentication information from the patient 2202 (due tothe increased risks and potential liability for displaying suchsensitive information to unauthorized persons). Thus, in this situation,the computer 2260 prompts (in Step 2406) the patient 2202 to provideboth a PIN and thumbprint. If the determination (in Step 2512) ispositive in this situation, then further processing (Step 2514) includesproviding the patient 2202 with access to the requested, sensitiveinformation. If the EC contains a request by the patient 2202 for themedical records access manager 2212 to perform an action on the accountor on information contained within the account, such as, for example, arequest to forward a specific medical record, report, or piece ofinformation to a third party, such as a hospital, insurance company, ormedical practitioner, such an EC can be processed as generally describedin FIGS. 24 and 25. In contrast with the above two ECs, however, thepurpose of obtaining a digital signature from the patient 2202 is notonly for entity authentication but primarily for “confirmation” of therequested action. In this scenario, if the entity authenticationinformation or status provided is sufficient (as determined in Step2512), then further processing (Step 2514) of the message includesperformance of the requested action.

vi. (Medical) Practice Management Account

A sixth business application 2600 implementing the two-party ABDS system200 of FIG. 2 is illustrated in FIG. 26. In this example, an accountholder comprising a medical professional 2602 possesses a device in theform of a personal item 2650, such as a watch (as shown), jewelry, keyring, or the like, which is capable of receiving and transmittingradio-frequency (RF) data transmissions to and from an RFreceiver/transmitter 2652. The personal item 2650 securely protectstherein a private key of a public-private key pair. In this example, theRF receiver/transmitter 2652 is connected via cable 2665 into a suitableport (USB, serial, parallel, etc.) of a personal computer 2660. Thepersonal computer 2660 is conventional in that it includes a monitor2662, a keyboard 2664, and a mouse 2666. In the present example, thecomputer 2660 also includes a microphone 2668 for receipt of audioinput, such as the voice of the medical professional 2602, for entityauthentication purposes.

The personal item 2650 is associated, among other accounts, with amedical practice management account maintained by an account authorityrepresented by a medical practice management server 2612. The computer2660 has installed thereon suitable database management and accesssoftware to enable it to interact, for example, over an internal orexternal network 2608 (in this case, it is an internal network) withinformation contained within an account database maintained by server2612.

Accounts maintained by the server 2612 are associated with accountrecords maintained in one or more account databases, collectivelyreferred to and illustrated in FIG. 26 by account database 2614. Withreference to FIG. 27, each authorized user of the account database 2614is identified by a unique account identifier comprising an accountnumber 2716. Each account number 2716 identifies within the accountdatabase 2614 account information 2740, including entity-specificinformation 2742 and accessible databases 2744. In accordance with thepresent invention, the account number 2716 also identifies public keyinformation 2718, which includes at least the public key of the user ofthe respective account. Also in accordance with a feature of the presentinvention, the account number 2716 identifies device profile information2770 for the device that retains the private key corresponding with thepublic key associated with the account.

In the example of FIG. 26, the entity-specific information 2742includes, for example, the name, position, field of practice, and alisting of the groups to which the account holder belongs (for adetermination of access rights to other database records and sub-records(not shown)). The list of accessible databases 2744 includes, forexample, group calendar, personal calendar, group contact list, personalcontact list, group patient list, personal contact list, list ofaccepted insurance policies/carriers, and the like. The public keyinformation 2718 of the account of the medical professional 2602includes the public key corresponding to the private key retained withinthe personal item 2650. The device profile information 2770 includesinformation specific to the personal item 2650.

As stated previously, an EC from the medical professional 2602 to theserver 2612 may be used for three different purposes: sessionauthentication, transaction authentication, and transactionconfirmation. For example, a common type of session authenticationoccurs in this business application when the medical professional 2602initially attempts to login to or otherwise access the databasemanagement and access software maintained on the computer 2660.Transaction confirmation is applicable in this business applicationwhen, for example, the medical professional 2602 requests the server2612 to perform an action upon a record of one of the patients containedwithin the database (e.g., updating or adding information) and theserver 2612 requires the medical professional 2602 to confirm such arequest by digitally signing the request with the personal item 2650(and, potentially, also providing additional entity authenticationinformation or status).

Regardless of which type of EC is communicated from the medicalprofessional 2602 to the server 2612, the basic methodology forcomposing and digitally signing the message (on the medical professionalend) and for authenticating the message and authenticating the entity(on the server end) is essentially the same. For example, turning now toFIG. 28, a transaction is initiated (Step 2802) when the medicalprofessional 2602 accesses the login screen for access to the variousmedical practice records maintained on server 2612 by connecting overthe internal network 2608 using computer 2660 or, after such login hasalready occurred, when the medical professional 2602 requestsinformation from the database or requests the server 2612 to perform anaction on information in the database. Next, the server 2612 causes thecomputer 2660 to prompt (Step 2804) the medical professional 2602 toinput Factor C entity authentication information, such as a voiceprint,by speaking into the microphone 2668.

Once the computer 2660 has obtained a suitable voiceprint, an electronicmessage is composed (Step 2806) for sending to the server 2612 forauthentication and access to database records. For initial login, thecomputer 2660 displays a menu of available accounts from which themedical professional 2602 can select. Preferably, such availableaccounts are stored within a memory on the personal item 2650 andretrieved by the computer 2660 for selection by the medical professional2602. Of course, if only one account is available in a memory on thepersonal item 2650, then that account is selected by default withoutrequiring specific selection by the medical professional 2602.Alternatively, the list of available accounts may be maintained inmemory on the computer 2660 itself and displayed for selection by themedical professional 2602. For post-login communications, the computer2660 displays, for example, a menu of available patient records that themedical professional 2602 is allowed to review and actions that can beperformed with respect to each such patient record. The computer 2660also displays, for example, group and personal calendars, address books,and electronic mailboxes to which the medical professional has accessrights.

Once the computer 2660 composes the message, it is transmitted (Step2808) via cable 2665 to the RF receiver/transmitter 2652, which thensends an RF signal (containing the message) to the personal item 2650for digital signing by the medical professional 2602. In this regard,upon receipt of an RF signal containing data representing the message,the personal item 2650 originates (Step 2810) a digital signature forthe message by first calculating a hash value for the data and thenencrypting the hash value using the private key retained within thepersonal item 2650. The personal item 2650 then outputs (Step 2812) thedigital signature, which is received by the RF receiver/transmitter2652, which forwards the same to the computer 2660. The computer 2660then transmits (Step 2814) the message and the digital signaturetherefor in an EC to the server 2612.

With reference to FIG. 29, the EC is received (Step 2902) by the server2612 from the computer 2660. The server 2612 then retrieves (Step 2904)from the account database 2614 the public key that is identified by theaccount number 2716. Using this public key, the server 2612 attempts toauthenticate (Step 2906) the message. If the message does notauthenticate (in Step 2908) using the public key, then the server 2612responds (Step 2910) with a rejection of the message (i.e., refusal togrant access to the account or to perform the requested action). If themessage authenticates (in Step 2908), then the server 2612 concludesthat the message, in fact, came from the person possessing the correctpersonal item 2650 associated with the identified account number2716—(i.e., Factor A Entity Authentication is obtained). The server 2612then determines (Step 2912) whether or not the Factor C entityauthentication information or status (e.g., voiceprint) provided issufficient for further processing of the specific message. If not, thenthe server 2612 responds (Step 2910) with a rejection of the messageand, again, such response may indicate the reason for the rejection. Ifthe entity authentication is sufficient (in Step 2912), then the server2612 further processes (Step 2914) the message.

For initial login, further processing of the message merely meansproviding the medical professional 2602 with access to the main userscreen displayed by the computer 2660. For subsequent communications,further processing often means displaying information obtained from thedatabase 2614 in response to suitable inquiries made by the medicalprofessional using the computer 2660. In some circumstances, forexample, if the message is a request by the medical professional 2602for access to sensitive information pertaining to one of his patients,the server 2612 may require stronger entity authentication informationfrom the medical professional 2602 (due to the increased risks andpotential liability for displaying such sensitive information tounauthorized persons). Thus, in this situation, the computer 2660prompts (in Step 2806) the medical professional 2602 to provide both aPIN (using the computer keyboard 3064) and voiceprint. If thedetermination (in Step 2912) is positive in this situation, then furtherprocessing (Step 2914) includes providing the medical professional 2602with access to the requested, sensitive information. If the EC containsa request by the medical professional 2602 for the server 2612 toperform an action on the account or on information contained within theaccount, such as, for example, a request to add or change information ona patient record to which the medical professional 2602 has rights tomodify or append, such an EC can be processed as generally described inFIGS. 28 and 29. In contrast with the above two ECs, however, the server2612 may require a digital signature for this EC primarily for“confirmation” of the requested action. In this scenario, if the entityauthentication information or status provided is sufficient (asdetermined in Step 2912), then further processing (Step 2914) of themessage includes performance of the requested action.

vii. Government Benefits Account

A seventh business application 3000 implementing the two-party ABDSsystem 200 of FIG. 2 is illustrated in FIG. 30. In this example, anaccount holder comprising a citizen 3002 possesses a device in the formof a personal item 3050, such as a watch, necklace or dog-tag (asshown), other jewelry, key ring, or the like, which is capable ofreceiving and transmitting radio-frequency (RF) data transmissions toand from an RF receiver/transmitter 3052. The necklace 3050 securelyprotects therein a private key of a public-private key pair. In thisexample, the RF receiver/transmitter 3052 is connected via cable 3065into a suitable port (USB, serial, parallel, etc.) of a personalcomputer 3060. The personal computer 3060 is conventional in that itincludes a monitor 3062, a keyboard 3064, and a mouse 3066. The necklace3050 is associated, among other accounts, with a governmental recordsaccount maintained by an account authority represented by a citizenrecords manager 3012. The computer 3060 has suitable web browsersoftware installed thereon to enable it to communicate over the Internet3008, in conventional manner, such as via a modem, LAN line, etc., witha secure web site hosted by citizen records manager 3012.

Accounts maintained by the citizen records manager 3012 are associatedwith account records maintained in one or more account databases,collectively referred to and illustrated in FIG. 30 by account database3014. With reference to FIG. 31, each authorized user of the accountdatabase 3014 is identified by a unique account identifier comprising anaccount number 3116. Each account number 3116 identifies within theaccount database 3014 account information 3140, includingcitizen-specific information 3142 and account-specific information 3144.In accordance with the present invention, the account number 3116 alsoidentifies public key information 3118, which includes at least thepublic key of the citizen associated with a respective account. Also inaccordance with a feature of the present invention, the account number3116 identifies device profile information 3170 for the device thatretains the private key corresponding with the public key associatedwith the account.

In the example of FIG. 30, the citizen-specific information 3142includes, for example, the name, address, social security number, tax-IDnumber, occupation, place of birth, age, and the like, of each citizen.The account-specific information 3144 includes, for example, SocialSecurity benefits, welfare benefits, Medicare/Medicaid benefits,Universal Prescription Drug benefits, Universal Healthcare benefits, taxreturns (electronic format for previous five years), bank accountinformation, and the like. The public key information 3118 of theaccount of the citizen 3002 includes the public key corresponding to theprivate key retained within the necklace 3050. The device profileinformation 3170 includes information specific to the necklace 3050.

In this business application, an EC from the citizen 3002 to the citizenrecords manager 3012 is generally only used for the purpose of sessionauthentication. For example, a first session authentication occurs whenthe citizen 3002 initially attempts to login to or otherwise access thesecure web site maintained by the citizen records manager 3012. Afurther session authentication occurs when the citizen 3002 requestsaccess to specific records or pieces of information that are verysensitive, secure, confidential, or private for the citizen 3002, inwhich case, the citizen records manager 3012 requires a stronger levelof entity authentication than is required merely to access the entrylevel of the secure web site.

Regardless of which session authentication EC is communicated from thecitizen 3002 to the citizen records manager 3012, the basic methodologyfor composing and digitally signing the message (on the citizen end) andfor authenticating the message and authenticating the entity (on thecitizen records manager end) is essentially the same. For example,turning now to FIG. 32, a transaction in accordance with the presentinvention is initiated (Step 3202) in the implementation illustrated inFIGS. 30 and 31 when the citizen 3002 initially accesses the loginscreen for access to the secure web site maintained by citizen recordsmanager 3012 by connecting over the Internet 3008 using computer 3060or, after such secure web site has been successfully accessed, when thecitizen 3002 requests access to very sensitive, secure, confidential, orprivate information, as stated above. Next, the secure web site causesthe computer 3060 to prompt (Step 3204) the citizen 3002 to provideFactor B or C entity authentication information, such as a PIN orbiometric information, by typing the PIN into the computer 3060 usingkeyboard 3064 or by providing a biometric sample to a suitable biometricreader (not shown) attached to or otherwise in electronic communicationwith the computer 3060.

In this case, once the PIN has been input, an electronic message iscomposed (Step 3206) for sending to the citizen records manager 3012 forauthentication and access to the citizen's personal records. For loginpurposes, the message need only contain the relevant account number. Forsubsequent transaction authentication communications or requests foraccess to information, the message includes an instruction (i1) from thecitizen 3002 to the citizen records manager 3012. For initial login, thecomputer 3060 displays a menu of available accounts from which thecitizen 3002 can select. Preferably, such available accounts are storedwithin memory on the necklace 3050 and retrieved by the RFreceiver/transmitter 3052 (as commanded by the computer 3060) forselection by the citizen 3002. Of course, if only one account isavailable in memory on the necklace 3050, then that account is selectedby default without requiring specific selection by the citizen 3002.Alternatively, the list of available accounts may be maintained inmemory on the computer 3060 itself and displayed for selection by thecitizen 3002. For post-login communications, the computer 3060 displays,for example, a menu of available citizen records and governmentalbenefit accounts that the citizen 3002 is allowed to view.

Once the appropriate account number or menu item is selected, thecomputer 3060 converts the information into a message, which istransmitted (Step 3208) via cable 3065 from the computer 3060 to the RFreceiver/transmitter 3052, which then sends an RF signal (containing themessage) to the necklace 3050 for digital signing by the citizen 3002.In this regard, upon receipt of an RF signal containing datarepresenting the message, the necklace 3050 originates (Step 3210) adigital signature for the message by first calculating a hash value forthe data and then encrypting the hash value using the private keyretained within the necklace 3050. The necklace 3050 then outputs (Step3212) the digital signature, which is received by the RFreceiver/transmitter 3052, which forwards the same to the computer 3060.The computer 3060 then transmits (Step 3214) the message and the digitalsignature therefor in an EC to the citizen records manager 3012.

With reference to FIG. 33, the EC is received (Step 3302) by the citizenrecords manager 3012 from the computer 3060. The citizen records manager3012 then retrieves (Step 3304) from the account database 3014 thepublic key that is identified by the account number 3116. Using thispublic key, the citizen records manager 3012 attempts to authenticate(Step 3306) the message. If the message does not authenticate (in Step3308) using the public key, then the citizen records manager 3012responds (Step 3310) with a rejection of the message (i.e., refusal togrant access to the account or to perform the requested action). If themessage authenticates (in Step 3308), then the citizen records manager3012 concludes that the message, in fact, came from the personpossessing the correct necklace 3050 associated with the identifiedaccount number 3116—(i.e., Factor A Entity Authentication is obtained).The citizen records manager 3012 then determines (Step 3312) whether ornot the Factor B or C entity authentication information or status (e.g.,PIN and/or biometric information) provided is sufficient for furtherprocessing of the specific message. If not, then the citizen recordsmanager 3012 responds (Step 3310) with a rejection of the message and,again, such response may indicate the reason for the rejection. If theentity authentication is sufficient (in Step 3312), then the citizenrecords manager 3012 further processes (Step 3314) the message.

For initial login, further processing of the message merely meansproviding the citizen 3002 with access to the main user screen of thesecure web site displayed by the computer 3060. For subsequentcommunications, further processing means displaying for the citizen 3002the requested citizen record or governmental benefit information. Asstated previously, for added security, the citizens records manager 3012may require additional digital signatures for some instructions andrequests made on the web site (e.g., transactional confirmation orfurther session authentication). If necessary, messages are generatedwhen the citizen 3002 selects particular options or menu items on theweb site. When such an option or item is selected, the citizens recordsmanager 3012 transmits a data packet of information to the computer 3060along with an instruction to request a digital signature. The computer3060, in response, transmits the information to the necklace 3050 via RFreceiver/transmitter 3052. This information constitutes a new message.To prevent unauthorized or unintentional digital signatures beinggenerated in response to unwanted RF signals transmitted to the necklace3050, it is preferable that the citizen records manager 3012 not trustan EC received from the necklace 3050 unless Factor B or C EntityAuthentication is performed.

viii. Internet Service Provider

An eighth business application 3400 implementing the two-party ABDSsystem 200 of FIG. 2 is illustrated in FIG. 34. In this example, anaccount holder 3402 comprising a person possesses a device in the formof a dongle 3450, which is directly plugged into a suitable port (USB,serial, parallel, etc.) on the back side of a personal computer 3460.The dongle 3450 securely protects therein a private key of apublic-private key pair. The personal computer 3460 is conventional inthat it includes a monitor 3462, a keyboard 3464, and a mouse 3466. Thedongle 3450 is associated specifically with an Internet Service Provideraccount maintained by an account authority represented by an InternetService Provider 3412. The computer 3460 has suitable web browsersoftware installed thereon to enable it to communicate over network3408, in conventional manner, such as via a modem, LAN line, etc., withthe Internet Service Provider 3412. The computer also has softwareinstalled that enables the computer 3460 to communicate with theattached dongle 3450.

Accounts maintained with the Internet Service Provider 3412 areassociated with account records maintained in one or more accountdatabases, collectively referred to and illustrated in FIG. 34 byaccount database 3414. With reference to FIG. 35, each account includesa unique account identifier comprising an account number 3516. Eachaccount number 3516 identifies within the account database 3414 accountinformation 3540, including customer-specific information 3542 andaccount-specific information 3544. In accordance with the presentinvention, the account number 3516 also identifies public keyinformation 3518, which includes at least a public key of an accountholder of the respective account. Also in accordance with a feature ofthe present invention, the account number 3516 identifies device profileinformation 3570 for the device that retains the private keycorresponding with the public key associated with the account.

In the example of FIG. 34, the customer-specific information 3542includes, for example, the name, billing address, email address, creditcard information, and the like of the account holder. Theaccount-specific information 3544 includes, for example, ISP connectionmeans (e.g., telephone modem, cable modem, ISDN, T1 connection, etc.)and speed, Internet hours used and available, email accounts andaliases, web page address(es), and the like. The public key information3518 of the account of the account holder 3402 includes the public keycorresponding to the private key retained within the dongle 3450. Thedevice profile information 3570 includes information specific to thedongle 3450.

In this business application, an EC from the account holder 3402 to theInternet Service Provider 3412 is generally only used for the purpose ofsession authentication (i.e., for initially logging-in to or otherwiseaccessing the Internet access portal of the Internet Service Provider3412 for the purpose of accessing the Internet). For this reason, theonly message that generally needs to be communicated from the accountholder 3402 to the Internet Service Provider 3412 is one that includesthe account number 3516 for the relevant account. The instruction (i1)(i.e., “give me access to the Internet”) is implicit in the merecommunication of the EC containing the account number.

As illustrated in FIG. 36, session authentication is initiated (Step3602) when the account holder 3402 activates the automated loginsoftware installed on the computer 3460 by “double-clicking” theInternet access icon on his computer desktop in conventional manner. Theautomated login software sends (Step 3604) a request for digitalsignature message from the computer 3460 to the dongle 3450 connectedthereto. In response, the dongle 3450 retrieves (Step 3606) the accountnumber from its internal memory and provides (Step 3608) the accountnumber, as the message, to the digital signing component of the dongle3450. Next, the dongle 3450 originates (Step 3610) a digital signaturefor the message by first calculating a hash value for the data and thenencrypting the hash value using the private key retained within thedongle 3450. The dongle 3450 then outputs (Step 3612) the digitalsignature, which is received by the computer 3460. The computer 3460then transmits (Step 3614) the message and the digital signaturetherefor in an EC to the Internet Service Provider 3412 in conventionalmanner.

With reference to FIG. 37, the EC is received (Step 3702) by theInternet Service Provider 3412 from the computer 3460. The InternetService Provider 3412 then retrieves (Step 3704) from the accountdatabase 3414 the public key that is identified by the account number3516. Using this public key, the Internet Service Provider 3412 attemptsto authenticate (Step 3706) the message. If the message authenticates(Step 3708), then the Internet Service Provider 3412 concludes that themessage is, in fact, from the computer 3460 having the legitimate dongle3450 connected thereto (which is presumably the computer 3460 of theaccount holder 3402) and provides (Step 3712) the computer 3460 withaccess to the Internet 3408. On the other hand, if the message does notauthenticate (in Step 3708), then the Internet Service Provider 3412responds (Step 3710) with a rejection of the message. Such a responsemay indicate the reason for the rejection.

Obviously, the above process does not provide very strong entityauthentication since any computer having the appropriate dongle 3450attached thereto is able to obtain access to the Internet (per Step3712). Should stronger entity authentication be desired, the aboveprocess can be modified to be more similar to the previous businessapplications, which require the account holder 3402 to provide Factor Band/or C entity authentication information. In this case, for example,the account holder 3402 may be required to input Factor B entityauthentication information, such as a PIN, which is transmitted by thecomputer 3460 to the dongle 3450 along with the above-mentioned “requestfor digital signature” message. The Internet Service Provider 3412 thendetermines (in a step not shown) whether the entity authenticationinformation or status provided by the account holder 3402 is sufficientenough for the Internet Service Provider 3412 to determine that theaccount holder 3402 is the entity sitting at the computer 3460. In thiscase, the EC is still used for session authentication.

ix. Employee Database Authorization Account

A ninth business application 3800 implementing the two-party ABDS system200 of FIG. 2 is illustrated in FIG. 38. In this example, an accountholder comprising a computer programmer 3802 possesses a device in theform of an electronic key 3850, which is designed to interface with anelectronic lock 3852, which is connected via cable 3865 into a suitableport (USB, serial, parallel, etc.) of a computer terminal 3860. Theelectronic key 3850 securely protects therein a private key of apublic-private key pair. The personal computer 3860 is conventional inthat it includes a monitor 3862, a keyboard 3864, and a mouse 3866. Theelectronic key 3850 is associated with an employee's databaseauthorization account maintained by an account authority represented, inthis example, by an authentication server 3812 operated by the employer(not shown) of the computer programmer 3802; the employer being engagedin the business of creating, designing, and writing computer programsand code. The computer 3860 has direct access over an internal computernetwork 3808 to the authentication server 3812, and indirect accessthrough server 3812 and through internal firewall 3894 to secure server3892, upon which is stored source code of a computer program upon whichthe legitimate computer programmer 3802 is authorized to work and needsaccess. Each time the computer programmer 3802 wants to access thesecure server 3892, however, the computer programmer 3802 must first beauthenticated and approved by the authentication server 3812.

Accounts maintained by the authentication server 3812 are associatedwith account records maintained in one or more account databases,collectively referred to and illustrated in FIG. 38 by account database3814. With reference to FIG. 39, each authorized user identified in theaccount database 3814 is identified by a unique account identifier (suchas an employee ID) comprising an account number 3916. Each accountnumber 3916 identifies within the account database 3814 accountinformation 3940, including employee-specific information 3942 andaccessible databases 3944. In accordance with the present invention, theaccount number 3916 also identifies public key information 3918, whichincludes at least the public key of the user of the respective account.Also in accordance with a feature of the present invention, the accountnumber 3916 identifies device profile information 3970 for the devicethat retains the private key corresponding with the public keyassociated with the account.

In the example of FIG. 38, the employee-specific information 3942includes, for example, the name, email address, department, supervisorname, authorized project (s) names, building location, room location,computer serial number, and the like. The list of accessible databases3944 includes, for example, a plurality of projects, identified hereinby project 1, project 2, project 3 up to project n. The public keyinformation 3918 of the account of the computer programmer 3802 includesthe public key corresponding to the private key retained within theelectronic key 3850. The device profile information 3970 includesinformation specific to the electronic key 3850. In this context, themessage from the computer programmer 3802 includes the account number3916 for the relevant account and an instruction to the authenticationserver 3812, for example, to provide access to the secure server 3892.

In this business application, an EC from the computer programmer 3802 tothe authentication server 3812 is generally only used for the purpose ofsession authentication (i.e., for initially obtaining access to theprotected computer program or source code maintained on secure server3892). For this reason, the only message that generally needs to becommunicated from the computer programmer 3802 to the authenticationserver 3812 is one that includes the account number 3916 for therelevant account and the name of the project, program, or source codefile upon which the computer programmer 3802 is authorized to work.

As illustrated in FIG. 40, session authentication is initiated (Step4002) when the computer programmer 3802 requests access to secure server3892. Such request is formulated using suitable operating systemcomputer commands on computer 3864 and presented to authenticationserver 3812. In response to the request, authentication server 3812causes the computer 3860 to prompt (Step 4004) the computer programmer3802 to insert the electronic key 3850 into electronic lock 3852 (if notalready done) and to provide Factor B entity authentication information,such as a PIN, by inputting the PIN into the computer 3860 usingkeyboard 3864. Once the key 3850 has been inserted into the lock 3852and once the PIN has been input, an electronic message is composed (Step4006) for sending to the authentication server 3812 for authenticationand approval for access to secure server 3892. The message is composed,for example, in the following manner.

The computer 3860 prompts the computer programmer 3802 to specify a“project name” for requested access. Once a project name is input, thecomputer 3860 combines the project name and account number 3916 into amessage for digital signing. The message is then transmitted (Step 4008)via cable 3865 from the computer 3860 to the lock 3852 and then into thekey 3850. Once the message is received by the key 3850, it originates(Step 4010) a digital signature for the message by first calculating ahash value for the data and then encrypting the hash value using theprivate key retained within the key 3850. The key 3850 then outputs(Step 4012) the digital signature, which is received by the lock 3852,which forwards the same to the computer 3860. The computer 3860 thentransmits (Step 4014) the message and the digital signature therefor inan EC to the authentication server 3812.

With reference to FIG. 41, the EC is received (Step 4102) by the server3812 from the computer 3860. The authentication server 3812 thenretrieves (Step 4104) from the account database 3814 the public key thatis identified by the account number 3916. Using this public key, theauthentication server 3812 attempts to authenticate (Step 4106) themessage. If the message does not authenticate (in Step 4108), then theserver 3812 responds (Step 4110) with a rejection of the message (i.e.,refusal to grant access to the secure server 3892). Such a response mayindicate the reason for the rejection. If the message authenticates (inStep 4108), then the authentication server 3812 concludes that themessage, in fact, came from the person possessing the correct electronickey 3850 associated with the identified account number 3916—(i.e.,Factor A Entity Authentication is obtained). The authentication server3812 then determines (Step 4112) whether or not the Factor B entityauthentication information or status (e.g., PIN) provided is sufficientfor further processing of the specific message. If not, then theauthentication server 3812 responds (Step 4110) with a rejection of themessage and, again, such response may indicate the reason for therejection. If the entity authentication is sufficient (in Step 4112),then the authentication server 3812 further processes (Step 4114) themessage. In this case, further processing includes a separatedetermination as to whether the computer programmer 3802 has any rightsor permissions associated with the requested program or file. If not,then the authentication server 3812 responds (Step 4110) with arejection of the message and, again, such response may indicate thereason for the rejection. If the computer programmer 3802 does have somerights or permissions with respect to the requested program or file,then the computer programmer 3802 is given access, as limited by thoserights and permissions.

x. Secure Area Authorization Account

A tenth business application 4200 implementing the two-party ABDS system200 of FIG. 2 is illustrated in FIG. 42. In this example, an accountholder 4202 comprising an employee possesses a device in the form of anelectronic key 4250, which is designed to interface with an electroniclock 4252, which is connected via cable 4265 into a suitable port of acontrol server 4292. The electronic lock 4252 also has associatedtherewith an alphanumeric keypad 4254 for input, for example, of a PIN,if necessary or desired. The electronic key 4250 securely protectstherein a private key of a public-private key pair. The control server4292 electronically controls via line 4267 the locking and unlockingmechanism 4263 associated with secure door 4262 into building 4260. Theelectronic key 4250 is associated with a secure area authorizationaccount maintained by an account authority represented by a securityaccount manager 4212 operated by the employer (not shown) of theemployee 4202. Each time the employee 4202 wants access to the building(or other secure areas that are not shown in this example), the employee4202 must first be authenticated and approved for access to therequested area by the security account manager 4212, which communicateswith the control server via line 4269.

Accounts maintained by the security account manager 4212 are associatedwith account records maintained in one or more account databases,collectively referred to and illustrated in FIG. 42 by account database4214. With reference to FIG. 43, each authorized user identified in theaccount database 4214 is identified by a unique account identifiercomprising an account number 4316. Each account number 4316 identifieswithin the account database 4214 account information 4340, includingemployee-specific information 4342, secured spaces or areas 4344, andaccess requirements 4346 associated with each secured space. Inaccordance with the present invention, the account number 4316 alsoidentifies public key information 4318, which includes at least thepublic key of the user of each respective account. Also in accordancewith a feature of the present invention, the account number 4316identifies device profile information 4370 for the device that retainsthe private key corresponding with the public key associated with theaccount.

In the example of FIG. 42, the employee-specific information 4342includes, for example, the name, email address, department, supervisorname, project(s) assignments, building location, room location, computerserial number, and the like. The list of secured spaces or areas 4344includes, for example, the parking lot, main building entrance, floors1–6, floors 7–10, room 610, other secure rooms, and other unspecifiedbut secured areas. The list of access requirements 4346 identifies what“type” of entity authentication is required for access to thecorresponding secured space 4344 (e.g., none—meaning that even a digitalsignature does not grant access to the corresponding space;device—meaning that presentation of a digital signature by the device issufficient for access; device+PIN—meaning that a digital signature fromthe device plus a correct PIN is required for access to thecorresponding space; device+BIO—meaning that a digital signature fromthe device plus a sufficient biometric specimen is required for accessto the corresponding-space; and device+PIN+BIO—meaning that a digitalsignature from the device plus a correct PIN plus a sufficient biometricspecimen is required for access to the corresponding space). Additionalbusiness rules implemented by the security account manager 4212determine how strong the entity authentication must actually be in orderto grant access to a requested area in the building 4260. The public keyinformation 4318 of the account of the employee 4202 includes the publickey corresponding to the private key retained within the electronic key4250. The device profile information 4370 includes information specificto the electronic key 4250. In this context, the message from theemployee 4202 includes the account (employee) number 4316 for therelevant account and an instruction to the security account manager4212, for example, to provide access to a specified space or area 4344.

In this business application, an EC from the employee 4202 to thesecurity account manager 4212 is generally only used for the purpose oftransaction authentication (i.e., for obtaining access to the requestedsecure area or resource). For this reason, the only message thatgenerally needs to be communicated from the employee 4202 to thesecurity account manager 4212 is one that includes the account number4316 for the relevant account. The instruction (i1) (i.e., “give meaccess to the area protected by this lock 4252”) is implicit in the merecommunication of the EC containing the account number 4316.

As illustrated in FIG. 44, transaction authentication is initiated (Step4402) when the employee 4202 attempts to access a secure space or area,such as main building entrance 4262 of main building 4260. This occurswhen the employee 4202 physically inserts the electronic key 4250 intoelectronic lock 4252 (since this particular lock 4252 is of the“contact” variety rather than of the “contactless” variety). The controlserver 4292 prompts (Step 4404), using an audible message that is outputfrom a speaker (not shown) near the secure door 4262, the employee 4202to input a PIN for Factor B entity authentication purposes by typing thePIN into the keypad 4254. With the key 4250 still inserted and after thePIN has been entered, an electronic message is composed (Step 4406) forsending to the server 4212 (via control server 4292) for authenticationand approval for access to the main building 4260. The message iscomposed, for example, by the control server 4292, which retrieves theaccount number 4316 from the key 4250 and combines it with the name (orcomputer identification number) of the secured door 4262 the employee4202 is trying to enter. Preferably, the control server 4292 alsoincludes a unique session key within the message to prevent thepossibility of a “replay attack” (i.e. reuse of a previous digitalsignature originated from the key 4250).

The message composed by the control server 4292 is then transmitted(Step 4408) via cable 4265 back to the key 4250 for the origination of adigital signature. Once the message is received by the key 4250, itoriginates (Step 4410) a digital signature for the message by firstcalculating a hash value for the data and then encrypting the hash valueusing the private key retained within the key 4250. The key 4250 thenoutputs (Step 4412) the digital signature to the lock 4252, whichforwards the same on to the control server 4292. The control server 4292then transmits (Step 4414) the message and the digital signaturetherefor in an EC to the security account manager 4212.

With reference to FIG. 45, the EC is received (Step 4502) by thesecurity account manager 4212 from the control server 4292. The securityaccount manager 4212 then retrieves (Step 4504) from the accountdatabase 4214 the public key that is identified by the account number4316. Using this public key, the security account manager 4212 attemptsto authenticate (Step 4506) the message. If the message does notauthenticate (in Step 4508), then the security account manager 4212responds (Step 4510) with a rejection of the message (i.e., refusal togrant access to the building 4260). Such a response may indicate thereason for the rejection. If the message authenticates (in Step 4508),then the security account manager 4212 concludes that the message, infact, came from the person possessing the correct electronic key 4250associated with the identified account number 4316—(i.e., Factor AEntity Authentication is obtained). The security account manager 4212then determines (Step 4512) whether or not the Factor B entityauthentication (e.g., PIN) provided is sufficient (based on the type ofentity authentication required for the particular door 4262 and based onthe above-mentioned business rules) for further processing of thespecific message. If not, then the security account manager 4212responds (Step 4510) with a rejection of the message and, again, suchresponse may indicate the reason for the rejection. If the entityauthentication is sufficient (in Step 4512), then the security accountmanager 4212 further processes (Step 4514) the message.

In this case, further processing includes a separate determination as towhether the employee 4202 has any right or permission to obtain accessto the requested secure area through secure door 4262. If not, then (andeven though the employee 4202 provided sufficient entity authentication)the security account manager 4212 responds (Step 4510) with a rejectionof the message (refusal to grant access to the requested area) and,again, such response may indicate the reason for the rejection. If theemployee 4202 does have rights or permissions to enter the requestedarea, then the security account manager 4212 provides the employee 4202with access to the requested area. More specifically, the securityaccount manager 4212 sends an appropriate signal to the control server4292, which, in turn, sends a signal via line 4267 to unlock and/or openthe entrance 4262.

xi. Electronic Data Interchange with Multiple Purchasing Agents

An eleventh business application 4600 implementing the two-party ABDSsystem 200 of FIG. 2 is illustrated in FIG. 46. In this example, twoaccount holders comprising purchasing agents 4602 a,4602 b each possessa device in the form of a card 4650 a,4650 b, respectively, such as anIC card, which is capable of being used in a card reader 4652 a,4652 b.Each card 4650 a,4650 b securely protects therein a private key of apublic-private key pair. In this example, each card reader 4652 a,4652 bis connected via cable 4665 a,4665 b into a suitable port (USB, serial,parallel, etc.) of a personal computer 4660 a,4660 b. Both personalcomputers 4660 a,4660 b are conventional in that they each include amonitor 4662 a,4662 b, a keyboard 4664 a,4664 b, and a mouse 4666 a,4666b. Both cards 4650 a,4650 b are associated with a corporate purchasingaccount maintained by an account authority represented by a supplycompany 4612. Both computers 4660 a,4660 b have installed thereonsuitable web browser software to enable them to communicate over theInternet 4608, in conventional manner, such as via a modem, LAN line,etc., with a web site hosted by the supply company 4612.

Accounts maintained with the supply company 4612 are associated withaccount records maintained in one or more account databases,collectively referred to and illustrated in FIG. 46 by account database4614. With reference to FIG. 47, each account includes a unique accountidentifier comprising an account number 4716. Each account number 4716identifies within the account database 4614 account information 4740,including account-specific information 4742 and purchasingagent-specific information 4744. In accordance with the presentinvention, the account number 4716 also identifies public keyinformation 4718, which includes at least a public key of eachpurchasing agent of each respective account. Also in accordance with afeature of the present invention, the account number 4716 identifiesdevice profile information 4770 for each device that retains a privatekey corresponding with the public key associated with the account.

In the example of FIG. 46, the account-specific information 4742includes, for example, company name, primary company contact, emailaddress, billing address, billing information, and list of authorizedpurchasing agents for the account. The purchasing agent-specificinformation 4744 includes, for example, agent name, purchasing agentidentification number, contact information for the purchasing agent,purchasing restrictions, if any, imposed by the company on thepurchasing agent, and the like. The public key information 4718 of theaccount of the company includes each public key corresponding to theprivate key retained within the cards 4650 a,4650 b of each purchasingagent. The device profile information 4770 includes information specificto each card 4650 a,4650 b. Although FIG. 46 illustrates only twopurchasing agents, FIG. 47 illustrates the fact that many morepurchasing agents (n) may also be associated with this particularcompany account.

As stated previously, an EC from the purchasing agent 4602 a,4602 b tothe supply company 4612 may be used for three different purposes:session authentication, transaction authentication, and transactionconfirmation. For example, a common type of session authenticationoccurs in this business application when the purchasing agent 4602a,4602 b initially attempts to login to or otherwise access the secureweb site operated by the supply company 4612. Transaction confirmationis applicable in this business application when, for example, thepurchasing agent 4602 a,4602 b requests the purchase of a high ticketitem and/or when the purchasing agent 4602 a,4602 b is ready to “checkout” and pay for the list of items purchased. In such case, the supplycompany 4612 requires the purchasing agent 4602 a,4602 b to confirm suchrequest by digitally signing the request with the card 4650 a,4650 b(and, potentially, also providing additional entity authenticationinformation or status).

Regardless of which type of EC is communicated from the purchasing agent4602 a,4602 b to the supply company 4612, the basic methodology forcomposing and digitally signing the message (on the purchasing agentend) and for authenticating the message and authenticating the entity(on the supply company end) is essentially the same. For example,turning now to FIG. 48, a transaction (in this case, sessionauthentication) is initiated (Step 4802) when either purchasing agent4602 a,4602 b accesses the web site of the supply company 4612 over theInternet 4608 using computer 4660 a,4660 b, respectively. For theremainder of this example, we will assume that this transaction isinitiated and carried out by the first purchasing agent 4602 a. First,the web site of the supply company causes the computer 4660 a to prompt(Step 4804) the purchasing agent 4602 a to input Factor B entityauthentication information, such as a PIN, into the login screen. Oncethe PIN has been input into the login screen, an electronic message iscomposed (Step 4806) for sending to the supply company 4612.

The message in this example is merely the account number 4716 associatedwith the corporate account maintained by the supply company 4612 onbehalf of the employer of both purchasing agents 4602 a,4602 b. Thecomputer 4660 a displays a menu of available accounts from which thepurchasing agent 4602 a can select. Preferably, such available accountsare stored within memory on the card 4650 a and retrieved by thecomputer 4660 a for selection by the purchasing agent 4602 a. Of course,if only one account is available in memory on the card 4650 a, then thataccount is selected by default without requiring specific selection bythe purchasing agent 4602 a. Alternatively, the list of availableaccounts may be maintained in memory on the computer 4660 a itself anddisplayed for selection by the purchasing agent 4602 a.

Once the appropriate account number is selected, it is transmitted (Step4808), as the message, via cable 4665 a from the computer 4660 a to thecard 4650 a for digital signing by the purchasing agent 4602 a. In thisregard, upon receipt of data representing the message, the card 4650 aoriginates (Step 4810) a digital signature for the message by firstcalculating a hash value for the data and then encrypting the hash valueusing the private key retained within the card 4650 a. The card 4650 athen outputs (Step 4812) the digital signature, which is received by thecomputer 4660 a. The computer 4660 a then transmits (Step 4814) themessage and the digital signature therefor in an EC to the supplycompany 4812.

With reference to FIG. 49, the EC is received (Step 4902) by the supplycompany 4612 from the computer 4660 a. The supply company 4612 thenretrieves (Step 4904) from the account database 4614 all of the publickeys that are identified by the account number 4716. Using each of thesepublic keys, the supply company 4612 sequentially attempts toauthenticate (Step 4906) the message. Alternatively, the message mayactually set forth the public key 4718 of the relevant purchasing agent4602 a (or an appropriate purchasing agent ID which acts as asub-account identifier) so that the supply company 4612 does not have to“guess” which public key 4718 from its database 4614 to use; however,the supply company 4612 would still need to confirm that such public key4718 corresponds with the specified account number 4716. If the messagedoes not authenticate (in Step 4908) with any of the public keysassociated with the identified account 4716, then the supply company4612 responds (Step 4910) with a rejection of the message (i.e., refusalto grant access to the web site for purchasing). Such a response mayindicate the reason for the rejection. Once the message authenticates(Step 4908), then the supply company 4612 concludes that the message, infact, came from the person possessing the correct card 4650 a associatedwith the identified account number 4716—(i.e., Factor A EntityAuthentication is obtained). The supply company 4612 then determines(Step 4912) whether or not the Factor B entity authenticationinformation or status (e.g., PIN) provided is sufficient for furtherprocessing of the specific message. If not, then the supply company 4612responds (Step 4910) with a rejection of the message and, again, suchresponse may indicate the reason for the rejection. If the entityauthentication is sufficient (in Step 4912), then the supply company4612 further processes (Step 4914) the message.

In this case, further processing includes providing the purchasing agent4602 a with access to the web site for purchasing supplies on behalf ofthe employer of the purchasing agent 4602 a. Further processing alsoincludes limiting display (or selection for purchase) of items that arenot within the purchasing authority of the purchasing agent 4602 a basedon the purchasing restrictions imposed on the particular purchasingagent 4602 a as set forth in the purchasing restrictions from thepurchasing agent-specific information 4744 in account database 4614.

Once in the web site, the purchasing agent 4602 a is allowed to navigatefreely around the web site (except as set forth above) and makepurchases on behalf of his employer. If desired, the supply company 4612may require additional entity authentication by the purchasing agent4602 a using the card 4650 a for “high-ticket” or specified items on theweb site. In such a case, preferably, the web site transmits aconfirmation message back to the computer 4660 a for transmission to thecard 4650 a for origination of a confirmation digital signature by thecard 4660 a. The process of originating such a digital signature willmirror the procedure as set forth above and may include re-entry ofFactor B entity authentication information or providing status of thesame prior to the generation of the digital signature.

i. Specific Implementations of 3-Party ABDS Systems

As with the two-party ABDS system 200 of FIG. 2, the three-party ABDSsystem 300 of FIG. 3 can be implemented in a vast number of businessapplications. The specific examples set forth herein, therefore,represent only a sampling of such wide-ranging possibilities.

i. eBusiness Transaction Using Financial Institution Account

A first business application 5000 implementing the three-party ABDSsystem 300 of FIG. 3 is illustrated in FIG. 50. In this example, anaccount holder comprising a purchaser 5002 possesses a device in theform of a card 5050, such as an IC card, which is capable of being usedin a card reader 5052. The card 5050 securely protects therein a privatekey of a public-private key pair. In this example, the card reader 5052is connected via cable 5065 into a suitable port (USB, serial, parallel,etc.) of a personal computer 5060. The personal computer 5060 isconventional in that it includes a monitor 5062, a keyboard 5064, and amouse 5066. The card 5050 is associated, among other accounts, with adebit or credit account maintained with an account authority comprisinga financial institution 5012. The account may be a checking account,savings account, money market account, credit card account, or the like,and the financial institution 5012 may be a bank, savings and loan,credit card company, or the like. The computer 5060 has installedthereon suitable web browser software to enable it to communicate overthe Internet 5008, in conventional manner, such as via a modem, LANline, etc., with an intermediate party comprising an on-line merchant5010.

Accounts maintained with the financial institution 5012 are associatedwith account records maintained in one or more account databases,collectively referred to and illustrated in FIG. 50 by account database5014. With reference to FIG. 51, each account includes a unique accountidentifier comprising an account number 5116. Each account number 5116identifies, within the account database 5014, account information 5140,including customer-specific information 5142 and account-specificinformation 5144. In accordance with the present invention, the accountnumber 5116 also identifies public key information 5118, which includesat least a public key of an account holder of each respective account.Also in accordance with a feature of the present invention, the accountnumber 5116 identifies device profile information 5170 for the devicethat retains the private key corresponding with the public keyassociated with the account.

In the example of FIG. 50, the customer-specific information 5142includes, for example, the name, address, social security number and/ortax-ID number of the account holder. The account-specific information5144 includes, for example, the current account balance, availablecredit, closing date and balance of current statement, and associatedaccount identifiers. The public key information 5118 of the account ofthe purchaser 5002 includes the public key corresponding to the privatekey retained within the card 5050. The device profile information 5170includes information specific to the card 5050.

With particular regard to FIG. 52, the purchaser 5002 initiates (Step5202) a transaction with on-line merchant 5010 by accessing the web siteof the on-line merchant 5010 using the web browsing software installedon the computer 5060 in conventional manner. While viewing the web siteon the computer 5060, the purchaser 5002 orders (Step 5206) a product,such as a book, from the on-line merchant 5010 by selecting the book forpurchase in conventional manner on the web site. Preferably, thepurchaser 5002 previously input (in Step 5204) Factor B or C entityauthentication information into the computer 5060 when the card 5050 wasinserted into the card reader 5052. If the card 5050 had not beenpreviously inserted into the card reader 5052, the computer 5060 nowprompts (Step 5204) the purchaser 5002 to do so and to input hisrelevant entity authentication information.

The step of generating a message (Step 5208), which will be digitallysigned, occurs as follows. As part of the ordering process, the web sitedisplays to the purchaser 5002 on monitor 5062 a payment selectionscreen, which, preferably, identifies the product being order andincludes the price of the product plus shipping and handling. Thepurchaser 5002 completes the required data entry field and/or makesselections from pull-down menus on the screen of monitor 5062 inconventional manner (e.g., such fields/menus could be automaticallyfilled in by the computer 5060 using information stored in “cookies” inknown manner) in order to specify payment method (i.e. account number5116 and type of account). Generally, it is not necessary to identifythe name of the financial institution 5012 since the financial industryuses conventions by which the identity can be derived solely from theaccount number 5116 (such as, for example, the use of issueridentification numbers (IIN) as defined in ISO Standard 7812, which isincorporated herein by reference). No other payment information need beentered in the payment selection screen. Rather than having to submitthe information to the on-line merchant 5010 in encrypted fashion, suchas with Secure Socket Layering (SSL), which is conventional, thepurchaser 5002 merely requests the option (on the payment method screen)of “digitally signing” the order in an “ABDS manner.” In response tothis selection, the computer 5060 generates a message, using theinformation displayed and/or input by the purchaser 5002 into thepayment selection screen(s).

This message is then transmitted (Step 5210) via cable 5065 from thecomputer 5060 to the card 5050 for digital signing by the purchaser5002. In this regard, upon receipt of data representing the message, thecard 5050 originates (Step 5212) a digital signature for the message byfirst calculating a hash value for the data and then encrypting the hashvalue using the private key retained within the card 5050. The card 5050then outputs (Step 5214) the digital signature, which is received by thecomputer 5060. The computer 5060 then transmits (Step 5216) the messageand the digital signature therefor in an EC to the on-line merchant5010.

In this particular example, the instructions (i2) from the purchaser5002 to the on-line merchant 5010 include the purchase order for theproduct using the payment method and account 5116 specified in themessage, with delivery going to the address, if any, provided by thepurchaser 5002; thus, portions of the instruction (i2) may have beenincluded in an electronic communication prior to the EC containing themessage and digital signature and additional portions of the instruction(i2) are included within the EC containing the message and digitalsignature. On the other hand, the message from the purchaser 5002, whichis intended ultimately for the financial institution 5012, includes theaccount number 5116 for the specified account and an instruction (i1) tothe financial institution 5012 to make a payment from the account 5116to the on-line merchant 5010 in the amount specified.

Unlike the two-party ABDS system 200, the EC containing the message anddigital signature (in this case used for transaction authenticationpurposes) is not sent directly to the financial institution 5012 butrather to the on-line merchant 5010. As illustrated in FIG. 53, theon-line merchant 5010 receives (Step 5302) the EC from the purchaser5002, extracts (Step 5304) any additional instructions (i2) from thepurchaser 5002 to the on-line merchant 5010 included within the ECcontaining the message and digital signature. The on line merchant 5010then forwards (Step 5306) the EC containing the message and digitalsignature to the financial institution 5012 for authentication andauthorization of payment. The on-line merchant 5010 then places (Step5308) these instructions (i2) (i.e., the purchase request) “on hold”pending approval of payment from the financial institution 5012, whileit waits (Step 5310) for a response from the financial institution 5012.

With reference to FIG. 54, the EC is received (Step 5402) by thefinancial institution 5012 from the on-line merchant 5010. The financialinstitution 5012 then retrieves (Step 5404) from the account database5014 the public key that is identified by the account number 5116. Usingthis public key, the financial institution 5012 attempts to authenticate(Step 5406) the message. If the message does not authenticate (in Step5408), then the financial institution 5012 responds (Step 5410) to theon-line merchant 5010 with a rejection of the message. Such a responsemay indicate the reason for the rejection. If the message authenticates(in Step 5408), then the financial institution 5012 concludes that themessage, in fact, came from the person possessing the correct card 5050associated with the identified account number 5116—(i.e., Factor AEntity Authentication is obtained). The financial institution 5012 thendetermines (Step 5412) whether or not the Factor B or C entityauthentication information or status provided is sufficient for furtherprocessing of the specific message. If not, then the financialinstitution 5012 responds (Step 5410) with a rejection of the messageand, again, such response may indicate the reason for the rejection. Ifthe entity authentication is sufficient (in Step 5412), then thefinancial institution 5012 proceeds with further processing (discussedbelow) of the message.

In the present example, further processing of the message includes adetermination (Step 5414) as to whether the instruction (i1) is capableof being performed. For example, even though the message authenticated,the purchaser may not have enough money or credit associated with theaccount for the financial institution 5012 to approve the transaction.Thus, making such a determination typically involves accessing therelevant portion(s) of the account record and confirming that the fundsare available. If the determination (in Step 5414) is negative, then thefinancial institution 5012 responds (Step 5410) to the on-line merchant5010 with a rejection of the message. Again, such a response mayindicate the reason for the rejection. If the determination in Step 5414is positive, then the financial institution 5012 performs (Step 5416)the instruction (i1). In this example, the instruction (i1) from thepurchaser 5002 is to pay the on-line merchant 5010 the specified amountof funds from the account for the purchase of the product. Thus,performing (Step 5416) the instruction typically involves accessing therelevant portion(s) of the account record, initiating transfer of thespecified amount of funds from the account of the purchaser 5002 to theon-line merchant 5010, and debiting/updating the account recordaccordingly. (It should be noted that the steps of transferring thefunds and debiting the account may not occur contemporaneously with theother steps). The financial institution 5012 also notifies (Step 5418)the on-line merchant 5010 of the approval of the message and theinitiation of the payment.

Referring back to FIG. 53, once the on-line merchant 5010 receives theresponse from the financial institution 5012, the determination in Step5310 is positive. The on-line merchant 5010 next determines (Step 5312)whether the response is an approval or rejection of the transaction. Ifthe transaction is not approved by the financial institution 5012, thenthe on-line merchant 5010 notifies (Step 5314) the purchaser 5002 thatthe message was rejected (i.e., payment was not approved) and that theinstructions (i2) are not being executed (i.e., that the product is notbeing shipped because of the payment rejection). On the other hand, ifthe determination in Step 5312 is positive, then the on-line merchant5010 executes (Step 5316) the instructions (i2) that had previously beenput on hold. In this case, the on-line merchant 5010 initiates shipmentof the product purchased by the purchaser 5002. Next, the on-linemerchant 5010 notifies (Step 5318) the purchaser 5002 that thetransaction (i.e. payment) was approved and that the instructions (i2)are being or have been executed (i.e., that the product is being shippedto the address as requested).

ii. Digital Gift Check Using Financial Institution Account

A second business application 5500 implementing the three-party ABDSsystem 300 of FIG. 3 is illustrated in FIG. 55. In this example, theaccount holder comprises a gift giver 5502, who possesses a device inthe form of a personal digital assistant (PDA) 5550. The PDA 5550securely protects therein a private key of a public-private key pair.The PDA 5550 includes an interactive display screen 5552 and user inputkeys 5556. Further, the PDA 5550 has been suitably equipped with awireless modem for digital communications over a wireless communicationsnetwork 5508. The PDA 5550 is associated with a debit or credit accountmaintained with an account authority comprising a gift clearing house orgift processor 5512. The account may be a checking account, savingsaccount, money market account, credit card account, or the like, and thegift processor 5512 may be a financial institution, such as bank,savings and loan, credit card company, or the like, or a company orbusiness unit specifically established for the purpose of enablingdigital checks or monetary gifts to be transmitted electronically withinan ABDS system. The PDA 5550 has installed thereon suitable software toenable it to generate and transmit an email over the network 5508, inconventional manner, to a gift recipient 5510, who has a computer 5590,which is capable of receiving and forwarding emails received over, forexample, the network 5508 and/or the Internet 5511. Alternatively, thePDA 5550 has installed thereon software provided by the gift processor5512 specifically for the purpose of composing, generating, and sendingsuch an email (or other electronic communication readable by email orstandard web browser software).

Accounts maintained with the gift processor 5512 are associated withaccount records maintained in one or more account databases,collectively referred to and illustrated in FIG. 55 by account database5514. With reference to FIG. 56, each account includes a unique accountidentifier comprising an account number 5616. Each account number 5616identifies, within the account database 5514, account information 5640,including customer-specific information 5642 and account-specificinformation 5644. In accordance with the present invention, the accountnumber 5616 also identifies public key information 5618, which includesat least a public key of an account holder of each respective account.Also in accordance with a feature of the present invention, the accountnumber 5616 identifies device profile information 5670 for the devicethat retains the private key corresponding with the public keyassociated with the account.

In the example of FIG. 55, the customer-specific information 5642includes, for example, the name, address, social security number and/ortax-ID number of the account holder. The account-specific information5644 includes, for example, the current account balance, availablecredit, current statement of the account holder, and payment accountalternatives. The public key information 5618 of the account of the giftgiver 5502 includes the public key corresponding to the private keyretained within the PDA 5550. The device profile information 5670includes information specific to the PDA 5550.

With particular regard to FIG. 57, the purchaser 5002 initiates thegiving of a digital check or monetary gift to the gift recipient 5510 bylaunching (Step 5702) the appropriate email or gift giving software(provided by the gift processor 5512) on the PDA 5550. If Factor B or Centity authentication information, such as a PIN or biometricinformation, had not already been input into the PDA 5550 by the giftgiver 5502, the PDA 5550 prompts (Step 5704) the gift giver 5502 to doso now.

Once such Factor B or C entity authentication information has beeninput, the gift giver 5502 generates (Step 5706) a message. This is doneeither by composing an email or composing a suitable “digital check”using the pre-installed software. Regardless, the message must containthe following information: name and email address of the gift recipient5510, amount of the gift, and the account number 5616 of the accountupon which the gift will be drawn. If the gift giver 5502 uses astandard email program, the appropriate email address or web address forthe gift processor 5512 must be included in the message composed, sothat the gift recipient 5510 knows where to go to claim the electronicgift or digital check. If the gift giver 5502 uses the preinstalledsoftware from the gift processor 5512, such software will automaticallyappend such appropriate contact information for the gift processor 5512into the message after the gift giver 5502 has composed it. Once suchmessage is completed, the gift giver 5502 digitally signs the messageusing the PDA 5550.

The PDA 5550 originates (Step 5708) a digital signature for the messageby first calculating a hash value for the data and then encrypting thehash value using the private key retained within the PDA 5550. The PDA5550 then outputs (Step 5710) the digital signature and message to the“outbox” within its email program. The PDA 5550 establishes a wirelessconnection with its email service provider over the network 5508 andtransmits (Step 5712) the message and the digital signature therefor inan EC in the form of an email to the gift recipient 5510—using the emailaddress for the gift recipient 5510 provided by the gift giver 5502 whengenerating the message.

As illustrated in FIG. 58, the gift recipient 5510 receives (Step 5802)the EC containing the message and digital signature (again, used in thiscase for transaction authentication purposes) using the standard emailsoftware the gift recipient 5510 has on computer 5590. Upon receipt ofthe EC, the gift recipient 5510 merely needs to forward (Step 5804) theEC containing the message and digital signature to the gift processor5512 for authentication and payment using the identified email or webaddress contained within the EC. Presumably, such email from the giftrecipient 5510 to the gift processor 5512 is transmitted via theInternet 5511 or other conventional communications network. The giftrecipient 5510 then merely waits for instructions from the giftprocessor 5512 for how to obtain the gift or for notification that thegift has been deposited in an account of the gift recipient 5510—ifarrangements between the gift recipient 5510 and gift processor 5512 arealready in place for such a deposit.

With reference to FIG. 59, the EC is received (Step 5902) by the giftprocessor 5512 from the gift recipient 5510. The gift processor 5512then retrieves (Step 5904) from the account database 5514 the public keythat is identified by the account number 5616. Using this public key,the gift processor 5512 attempts to authenticate (Step 5906) themessage. If the message does not authenticate (in Step 5908), then thegift processor 5512 responds (Step 5910) to the gift recipient 5510 witha rejection of the message. Such a response may indicate the reason forthe rejection. If the message authenticates (in Step 5908), then thegift processor 5512 concludes that the message, in fact, came from theperson possessing the correct PDA 5550 associated with the identifiedaccount number 5616—(i.e., Factor A Entity Authentication is obtained).The gift processor 5512 then determines (Step 5912) whether or not theFactor B or C entity authentication information or status provided issufficient for further processing of the specific message. If not, thenthe gift processor 5512 responds (Step 5910) with a rejection of themessage and, again, such response may indicate the reason for therejection, if desired. If the Factor B or C entity authenticationinformation or status is sufficient (in Step 5912), then the giftprocessor 5512 proceeds with further processing (discussed below) of themessage.

In the present example, further processing of the message includes adetermination (Step 5914) as to whether the instruction (i1) is capableof being performed. For example, even though the message authenticated,the gift giver 5502 may not have enough money or credit associated withthe account for the gift processor 5512 to approve the transaction.Thus, making such a determination typically involves accessing therelevant portion(s) of the account record and confirming that the fundsare available. If the determination (in Step 5914) is negative, then thegift processor 5512 responds (Step 5910) to the gift recipient 5510 witha rejection of the message. Again, such a response may indicate thereason for the rejection. If the determination in Step 5914 is positive,then the gift processor 5512 performs (Step 5916) the instruction (i1).In this example, the instruction (i1) from the gift giver 5502 is to paythe gift recipient 5510 the specified amount of funds from the accountas a gift or donation, as the case may be. Thus, performing (Step 5916)the instruction typically involves accessing the relevant portion(s) ofthe account record, conditionally debiting the specified amount of fundsfrom the account of the gift giver 5502 and updating the account recordaccordingly. The gift processor 5512 then notifies (Step 5918) the giftrecipient 5510 of the approval of the message and, if necessary,provides the gift recipient 5510 with instructions for obtaining themonetary amount of the gift.

Referring back to FIG. 58, the gift recipient 5510 then receives (Step5806) the response from the gift processor 5512 (which includesinstructions for obtaining the gift if the gift recipient 5510 does notalready have an account setup with the gift processor 5512 for receivingsuch gift amount).

iii. Point of Sale Transaction Using Financial Institution Account

A third business application 6000 implementing the three-party ABDSsystem 300 of FIG. 3 is illustrated in FIG. 60. In this example, anaccount holder comprising a purchaser 6002 possesses a device in theform of a card 6050, such as an IC card, which is capable of being usedat a point of sale location. A point of sale card reader 6052 includesan alphanumeric keypad 6056, a display 6054, and, in this case, athumbprint reader 6058. The point of sale card reader 6052 is incommunication via data connector 6064 with a merchant cashregister/terminal 6060, which has its own display 6062. The point ofsale card reader 6052 is also in communication with a standard financialnetwork 6008, which is in communication with and has the capability ofcorrectly routing communications between merchants and various financialinstitutions represented, in this example, by financial institutions6012,6022,6032. Each financial institution 6012,6022,6032 is, forexample, a bank, savings and loan, credit card company, and the like.Accounts maintained with the financial institutions 6012,6022,6032 areassociated with account records maintained in one or more accountdatabases, collectively referred to and illustrated in FIG. 60 byaccount databases 6014,6024,6034, respectively. In this example,financial institution 6012 maintains a banking or credit card account onbehalf of the authorized user of the card 6050. It is also assumed, inthis example, that the card 6050 is associated with the account of theauthorized user of the card 6050 in account database 6014.

With reference to FIG. 61, each account in database 6014 includes aunique account identifier comprising an account number 6116. Eachaccount number 6116 identifies, within the account database 6014,account information 6140, including customer-specific information 6142and account-specific information 6144. In accordance with the presentinvention, the account number 6116 also identifies public keyinformation 6118, which includes at least a public key of an accountholder of each respective account. Also in accordance with a feature ofthe present invention, the account number 6116 identifies device profileinformation 6170 for the device that retains the private keycorresponding with the public key associated with the account.

In the example of FIG. 60, the customer-specific information 6142includes, for example, the name, address, social security number and/ortax-ID number of each account holder. The account-specific information6144 includes, for example, the current account balance, availablecredit, closing date and balance of current statement, and associatedaccount identifiers. The public key information 6118 of the account ofthe purchaser 6002 includes the public key corresponding to the privatekey retained within the card 6050. The device profile information 6170includes information specific to the card 6050.

With particular regard to FIG. 62, the purchaser 6002 initiates (Step6202) a transaction with a merchant when the purchaser 6002 requests topay for an item at the merchant cash register/terminal 6060. Themerchant “rings up” (Step 6204) the item on the merchant cashregister/terminal 6060 and the total balance due is displayed to thepurchaser 6002 on the display 6062. To pay, the purchaser 6002 inserts(Step 6206) the card 6050 into the point of sale card reader 6052 (orbrings the card 6050 into proximity to the card reader 6052 if both thecard reader 6052 and the card 6050 are equipped for contactlessproximity communications in accordance with ISO/IEC Standard 14443,which is incorporated herein by reference). Upon insertion (orapproach), the point of sale card reader 6052 is initialized (Step6208), which, at a minimum, provides power from the point of sale cardreader 6052 to the card 6050.

Next, the merchant cash register/terminal 6060 transmits (Step 6210) thebalance due to the point of sale card reader 6052 via data connector6064. The point of sale card reader 6052 displays (Step 6212) thebalance due on display 6054. Preferably, the point of sale card reader6052 retrieves (Step 6214) a list of all available (or at least the twoto five primary) payment accounts maintained in memory on the card 6050and displays (Step 6216) them for selection by the purchaser 6002. Ifthere is more than one account from which to choose, the purchaser 6002then selects (Step 6218) one of the listed accounts (or a plurality ofaccounts if the amount of the purchase is going to be split between oramong more than one account). The display 6054 prompts (Step 6220) thepurchaser 6002 to provide Factor B and C entity authenticationinformation, such as a PIN and right thumbprint, using the alphanumerickeypad 6056 and thumbprint scanner 6058—but only if he approves of theproposed transaction (including amount of the purchase and the use ofthe selected account(s) for payment). Once the PIN and thumbprint havebeen input, the point of sale card reader 6052 transmits (Step 6222) thePIN and digitized version of the thumbprint to the card 6050. The cardreader 6052 next transmits (Step 6224) data representing the message tothe card 6050 for digital signature.

In this regard, upon receipt of data representing the message, the card6050 originates (Step 6226) a digital signature for the message by firstcalculating a hash value for the data and then encrypting the hash valueusing the private key retained within the card 6050. The card 6050 thenoutputs (Step 6228) the digital signature, which is received by thepoint of sale card reader 6052. The point of sale card reader 6052 thentransmits (Step 6230) the message and the digital signature therefor inan EC to the financial institution 6012 (via financial network 6008) andwaits (Step 6232) for a response from the financial institution 6012. Inthis case, the EC is used for transaction authentication purposes.

With reference to FIG. 63, after the financial network 6008 hascorrectly routed the EC, it is received (Step 6302) by the financialinstitution 6012 from the point of sale card reader 6052. The financialinstitution 6012 then retrieves (Step 6304) from the account database6014 the public key that is identified by the account number 6116. Usingthis public key, the financial institution 6012 attempts to authenticate(Step 6306) the message. If the message does not authenticate (in Step6308), then the financial institution 6012 responds (Step 6310) to themerchant (via financial network 6008 and point of sale card reader 6052)with a rejection of the message. Such a response may indicate the reasonfor the rejection. If the message authenticates (in Step 6308), then thefinancial institution 6012 concludes that the message, in fact, camefrom the person possessing the correct card 6050 associated with theidentified account number 6116—(i.e., Factor A Entity Authentication isobtained). The financial institution 6012 then determines (Step 6312)whether or not the Factor B and C entity authentication information(e.g., PIN and thumbprint) provided is sufficient for further processingof the specific message. If not, then the financial institution 6012responds (Step 6310) to the merchant (via financial network 6008 andpoint of sale card reader 6052) with a rejection of the message. Such aresponse may indicate the reason for the rejection, if desired. If theentity authentication is sufficient (in Step 6312), then the financialinstitution 6012 proceeds with further processing (discussed below) ofthe message.

In the present example, further processing of the message includes adetermination (Step 6314) as to whether the instruction (i1) is capableof being performed. If it is not possible to execute the instruction(i1), then the financial institution 6012 responds (Step 6310) with arejection of the message. For example, even though the messageauthenticated, the purchaser 6050 may not have enough money or creditassociated with the account for the financial institution 6012 toapprove the transaction. Thus, making such a determination typicallyinvolves accessing the relevant portion(s) of the account record andconfirming that the funds are available. If the determination (in Step6314) is negative, then the financial institution 6012 responds (Step6310) to the merchant (via financial network 6008 and point of sale cardreader 6052) with a rejection of the message. Again, such a response mayindicate the reason for the rejection. If the determination in Step 6314is positive, then the financial institution 6012 performs (Step 6316)the instruction (i1). In this example, the instruction (i1) from thepurchaser 6002 is to pay the merchant the specified amount of funds fromthe specified account for the purchase of the product. Thus, performing(Step 6316) the instruction typically involves accessing the relevantportion(s) of the account record, initiating transfer of the specifiedamount of funds from the account of the purchaser 6002 to the merchant(in known manner), and debiting/updating the account record accordingly.(As stated in a previous business application, the above processing ofthe instruction does not necessarily take place contemporaneously withthe other steps described herein). The financial institution 6012 alsonotifies (Step 6318) the merchant (via financial network 6008 and pointof sale card reader 6052) of the approval of the transaction.

Referring back to FIG. 62, once the merchant receives the response fromthe financial institution 6012, the determination in Step 6232 ispositive. The merchant next determines (Step 6234) whether the responseis an approval or rejection of the transaction. If the financialinstitution 6012 does not approve the transaction, then the merchantnotifies (Step 6236) the purchaser 6002 that the transaction was notapproved. On the other hand, if the determination in Step 6234 ispositive, then the merchant completes the sale (Step 6238) by giving thepurchaser 6002 the merchandise and a receipt.

As can be seen from the above example, the EC from the purchaser 6002acts as a transaction authentication for the requested purchase andpayment method even though it may, in fact, pass through many “hands”(via the financial network 6008) before it finally reaches the financialinstitution 6012 for processing and authentication.

2. The “Person-Centric Device”

The second aspect of the present invention incorporates the ABDS systemof the first aspect of the present invention, and includes, in additionthereto, the association of the public key (PuK) of a device of anaccount holder with multiple accounts rather than a single account.Furthermore, of the multiple accounts, some accounts may be maintainedby the same account authority (as shown by the third potential setupdescribed in association with FIG. 2 a) and some accounts may bemaintained by separate account authorities. Since the same device isassociated with multiple accounts and is not representative of anysingle account, but rather, is representative of the account holder,such a device is referred to herein as a “person-centric device.” Itwill be immediately apparent that the person-centric device enables theaccount holder to register the single device for use with multipleaccounts, thereby eliminating the need to have a multitude of creditcards, IC cards, ID cards, and the like. For example, a person-centricdevice can be associated with one or more bank accounts, credit cardaccounts, frequent flyer accounts, frequent diner accounts, gas cardaccounts, calling card accounts, building ID accounts, parking deckaccounts, and the like.

When used, the person-centric device originates a digital signature fora message just like the devices as described with regard to the firstaspect of the present invention. Specifically, the person-centric devicegenerates a digital signature by encrypting a hash value of messageusing the private key retained in the person-centric device. Also, insome embodiments of the device, the person-centric device calculates thehash value of the message by applying the appropriate hashing algorithm.Further, in some embodiments, the person-centric device also composesthe message.

The message itself is the same as described with regard to the firstaspect of the invention; namely, it includes an instruction and a uniqueidentifier corresponding to an account. However, in the ABDS systemutilizing the person-centric device, the unique identifier in aparticular message must correspond to an account maintained by theaccount authority that receives the message. In order to insure deliveryof the electronic communication over the communications medium to theproper account authority, the electronic communication is sent over aclosed communications medium that is dedicated to the particular accountauthority or, if the communications medium is an open network such asthe Internet, the electronic communication needs to include enoughinformation to identify the account authority that needs to receive theelectronic communication for authentication and approval of the message.Identification of the appropriate account authority may be accomplishedin many different ways. For example, the account number itself mayprovide any intermediate or routing entities with sufficient informationto know which account authority should receive the electroniccommunication. In another example, such information may be directlyinput into the message by the account holder during the composition of amessage or by the device or I/O support element during the messagecomposition or as part of the transmission of the electroniccommunication.

a. Two-Party ABDS System Using Person-Centric Device

Referring now to FIG. 64, a first preferred implementation of an ABDSsystem 6400 utilizing a “generic” person-centric device 6450 isillustrated. The person-centric device 6450 can be similar or identicalto any of the devices previously described with regard to the firstaspect of the invention. Thus, the person-centric device 6450 securelyprotects a private key of a public/private key pair therein. Further,the person-centric device 6450 is able to communicate over thecommunications medium 6408, which includes the Internet, in the samemanner in which any of the previously described devices communicate.

The ABDS system 6400 also includes a device user who becomes an accountholder 6402 once at least one account has been established with one ofthe account authorities 6412,6422,6432. Each of the account authorities6412, 6422, 6432 maintains one or more account databases, collectivelyreferred to and illustrated in FIG. 64 by account database6414,6424,6434, respectively. As in the first aspect of the presentinvention, each of these account databases 6414,6424,6434 maintainsrecords of account holders, and the database records are indexed byunique identifiers, preferably represented by unique account numbers.

In the present illustration, the account holder 6402 has established oneaccount with account authority 6412, the account having a uniqueidentifier designated by “acctID(a).” The account holder 6402 has alsoestablished one account with account authority 6422, this account havinga unique identifier designated by “acctID(b).” Additionally, the accountholder 6402 has established two accounts with account authority 6432,one account having a unique identifier designated by “acctID(c1)” andthe other account designated by “acctID(c2).” It should be noted thateven though the account holder 6402 has four different accounts withthree different account authorities, each account database recordincludes therein the same public key (PuK) as shown in FIGS. 64 a,64b,64 c. The process by which account holder 6402 registers theperson-centric device 6450 and, correspondingly, the public key of theperson-centric device 6450 with each respective account authority6412,6422,6432 is comparable to the registration process described forthe first aspect of the present invention.

The process by which the account holder 6402 communicates directly withany one of the account authorities 6412,6422,6432 is also the same as orsimilar to any one of the processes described with regard to thetwo-party ABDS system 200 of FIG. 2 and any of the specific two-partyABDS business applications described in FIGS. 6–49. For example, asshown in FIG. 65, the account holder 6402 initiates a communication withany specific one of the account authorities 6412,6422,6432 first byestablishing (Step 6502) an electronic connection with the desiredaccount authority. Next, the account holder 6402 inputs (Step 6504)entity authentication information, such as a PIN, password, passphrase,or biometric information, associated with the device 6450 into thedevice 6450. Next the account holder 6402 generates (Step 6506) amessage. If not already in the device 6450, the message is thenimported/transmitted (Step 6508) into the person-centric device 6450,which originates (Step 6510) a digital signature for the message byfirst calculating a hash value for the data and then encrypting the hashvalue using the private key retained within the device 6450. In analternative and less preferred embodiment, the hash value of the messageis calculated outside of the device and then provided to the devicemerely for the purpose of encryption of such hash value for the digitalsignature. The device 6450 then outputs (Step 6512) the digitalsignature from the digital signature component of the device. Themessage and digital signature therefore are then transmitted (Step 6514)to the appropriate account authority.

It should be noted that the exact process of generating a message andthe process of generating a digital signature for the message will varydepending upon the specific form of the person-centric device 6450 andthe particular environment in which it is used (e.g. use with an I/Osupport element). For example, if the person-centric device 6450 is acell phone or PDA, the message and the hash value of the message ispreferably generated and calculated, respectively, directly on theperson-centric device 6450 and then digitally-signed. If theperson-centric device 6450 is a dongle, an electronic key used incombination with an electronic lock, or a card used in combination witha card reader, all of which are preferably used in conjunction with theaccount holder's computer, then the message is generated on or receivedby the computer, the hash value is either generated by the computer andtransmitted to the person-centric device 6450 or the person-centricdevice 6450 receives the message and generates the hash value itself,and then the person-centric device 6450 originates the digital signaturefor the message. If the person-centric device is a subcutaneous implant,a personal item, or a card capable of being used at a public interfacelocation, such as an ATM machine, a card reader, an RFreceiver/transmitter, or point of sale reader, then the message and hashvalue of the message are preferably generated external from theperson-centric device 6450, the hash value is transmitted to theperson-centric device 6450, and then the person-centric device 6450originates the digital signature for the message.

Preferably, regardless of the particular type of person-centric device6450 used, each account number (or associated unique account identifier)is stored in memory within the person-centric device 6450.

Finally, the person-centric device 6450, with or without assistance froman I/O support element or other external apparatus, transmits themessage and digital signature in an electronic communication over thecommunications medium 6408 to the particular account authority withwhich the person-centric device 6450 has already established anelectronic connection. Regardless of how the message is generated above,it preferably includes the unique account identifier and the instruction(i1) to be executed by the account authority. In addition, as long asthe person-centric device 6450 is communicating with an accountauthority with which he has only one registered account associated withthe public key, the unique account identifier can actually be the publickey itself. Thus, the public key is usable as the unique accountidentifier for direct two party communications between the accountholder 6402 and account authorities 6412 and 6422, but not forcommunications with account authority 6432, which maintains two separateaccounts for the account holder 6402, both of which are associated withthe same public key.

The steps performed by the account authority 6412,6422,6432 in responseto an electronic communication received from the account holder 6402 areessentially the same as the steps performed by the particular accountauthority in any of the specific two-party ABDS business applications ofFIGS. 6–49 with the only variation arising from the contents of theinstruction (i1) and the type of business in which the account authorityis engaged or the type of account which is maintained by the accountauthority. The generic steps performed are set forth in FIG. 66 andinclude the steps of: receiving the electronic communication (Step6602), retrieving the public key from the associated record in theaccount database (Step 6604), and attempting to authenticate (Step 6606)the message using the public key so obtained. If the messageauthenticates (in Step 6608), the account authority then determines(Step 6612) whether sufficient entity authentication has been provided.If there has been sufficient entity authentication, then the accountauthority further processes (Step 6614) the message, which includesperforming (or at least attempting to perform) the instruction (i1). Ifthe message does not authenticate (in Step 6608), if there is notsufficient entity authentication (in Step 6612), or if it is notpossible to execute the instruction (i1) (in Step 6614), then theaccount authority responds (Step 6610) to the sender of the electroniccommunication with a rejection of the message and, potentially, with abasis or reason for the rejection.

b. Three-Party ABDS System Using Person-Centric Device

Referring now to FIG. 67, a second preferred implementation of an ABDSsystem 6700 utilizing a person-centric device 6750 is illustrated. Theonly significant differences between this second preferredimplementation of FIG. 67 and the first preferred implementation of FIG.64 are the addition of intermediate party 6710 and the fact that anelectronic communication from the account holder 6702 to one of theaccount authorities 6712,6722,6732 is communicated to the intermediateparty 6710, which then forwards an electronic communication to theappropriate account authority 6712,6722, or 6732 designated by theaccount holder 6702. The methodology of a three-party ABDS transactionwith a person-centric device 6750 is quite similar to the methodology ofa three-party ABDS transaction previously described with reference toFIGS. 50–63.

With particular regard to FIG. 68, the account holder 6702 initiates atransaction (Step 6802) with intermediate party 6710 first byestablishing an electronic connection over communications medium 6708with the intermediate party 6710 using the person-centric device 6750.Again, the exact form of the person-centric device 6750 may vary but issimilar or identical to any of the devices described with regard to thefirst aspect of the invention. Preferably, the account holder 6702 nextinputs (Step 6804) entity authentication information, such as a PIN,password, passphrase, or biometric information, associated with thedevice 6750 into the device 6750. By means of the electronic connection,the account holder 6702 formulates (Step 6806) an instruction (i2) thatthe account holder 6702 wants the intermediate party 6710 to perform. Inorder for the intermediate party 6710 to perform the instruction (i2),the intermediate party 6710 needs authorization and approval from one ofthe account holder's account authorities 6712,6722,6732. For thisreason, the account holder 6702 generates (Step 6808) a message for thepurpose of obtaining such authorization and approval from theappropriate account authority.

In order for the intermediate party 6710 to know which of the accountholder's account authorities should receive the message, either theaccount number itself should identify the appropriate account authorityor the electronic communication should indicate which account authority(AA#) needs to receive the electronic communication for authenticationand approval of the transaction.

Once the message has been composed, it should be transmitted/provided(Step 6810) to the device 6750 (unless the message was actually composedby or within the device 6750). The device 6750 then originates (Step6812) a digital signature for the message by first calculating a hashvalue for the data and then encrypting the hash value using the privatekey retained within the device 6750. In an alternative and lesspreferred embodiment, the hash value of the message is calculatedoutside of the device 6750 and then provided to the device 6750 merelyfor the purpose of encryption of such hash value for the digitalsignature. The device 6750 then outputs (Step 6814) the digitalsignature from the digital signature component of the device 6750. Themessage, digital signature therefore, and instruction (i2) are thentransmitted (Step 6816) to the intermediate party 6710 via thecommunications medium 6708. As described in other places throughout thisspecification, the person-centric device 6750 may require the assistanceof an I/O support element or other external device (not shown) in orderto complete the step of transmitting the electronic communication to theintermediate party 6710.

As illustrated in FIG. 69, the intermediate party receives (Step 6902)the electronic communication from the account holder 6702. Theintermediate party 6710 extracts (Step 6904) any instructions (i2) fromthe account holder 6702 to the intermediate party 6710, includinginformation (AA#) as to the identity of the account authority that needsto receive the forwarded electronic communication. As shown in FIG. 67,the instructions (i2) inform the intermediate party 6710 that accountauthority 6712 is the appropriate account authority for receiving theforwarded electronic communication. The intermediate party 6710 forwards(Step 6906) the electronic communication containing the message anddigital signature to the account authority 6712 for authentication andapproval of the instruction (i1). The intermediate party 6710 thenplaces (Step 6908) these instructions (i2) (e.g., the purchase request)“on hold” pending approval of the message payment from the accountauthority 6712, while it waits (Step 6910) for a response from theaccount authority 6712.

Referring now to FIG. 70, the steps performed by the account authority6712 in response to an electronic communication received from theaccount holder 6702 via the intermediate party 6710 will now bediscussed in greater detail. First, the account authority 6712 receives(Step 7002) the electronic communication from the intermediate party6710. Using the account number (acctID(#)) provided in the electroniccommunication, the account authority 6712 retrieves (Step 7004) thepublic key from the associated record in the account database 6714.Using this public key, the account authority 6712 attempts toauthenticate (Step 7006) the message. If the message does notauthenticate (in Step 7008), then the account authority 6712 responds(Step 7010) with a rejection of the message. Such a response mayindicate the reason for the rejection. If the message authenticates (inStep 7008), then the account authority 6712 concludes that the message,in fact, came from the person possessing the correct device 6750associated with the identified account number—(i.e., Factor A EntityAuthentication is obtained). The account authority 6712 then determines(Step 7012) whether or not the entity authentication provided issufficient for further processing of the specific message. If not, thenthe account authority 6712 responds (Step 7010) with a rejection of themessage. Such a response may indicate the reason for the rejection. Ifthe entity authentication is sufficient (in Step 7012), then the accountauthority 6712 proceeds with further processing (discussed below) of themessage.

The further processing of the message includes a determination (Step7014) as to whether the instruction (i1) is capable of being performed.For example, even though the message authenticates, the account of theaccount holder 6702 may not be authorized or capable of handling theinstruction (i1) in such a manner for the account authority 6712 toapprove the instruction (i1) or message. If the determination (in Step7014) is negative, then the account authority 6712 responds (Step 7010)to the intermediate party 6710 with a rejection of the message. Again,such a response may indicate the reason for the rejection. If thedetermination in Step 7014 is positive, then the account authority 6712performs (Step 7016) the instruction (i1). The account authority 6712also notifies (Step 7018) the intermediate party 6710 of the approval ofthe message and the execution of instruction (i1).

Referring back to FIG. 69, once the intermediate party 6710 receives theresponse from the account authority 6712, the determination in Step 6910is positive. The intermediate party 6710 next determines (Step 6912)whether the response is an approval or rejection of the transaction. Ifthe account authority 6712 does not approve the transaction, then theintermediate party 6710 notifies (Step 6914) the account holder 6702that the message was rejected and that the instructions (i2) are notbeing executed. On the other hand, if the determination in Step 6912 ispositive, then the intermediate party 6710 executes (Step 6916) theinstructions (i2) that had previously been put on hold. Next, theintermediate party 6710 notifies (Step 6918) the account holder 6702that the transaction was approved and that the instructions (i2) arebeing or have been executed.

3. The Central Key Authority

The third aspect of the present invention incorporates the ABDS systemof the first and second aspects of the present invention and includes,in addition thereto, the maintenance of a database of certain PuK-linkedaccount information (herein “Registration Information”) of a user of adevice. In other words, the database identifies a plurality of accountswith which a public key is associated. The entity that maintains thisdatabase is referred to herein as a “Central Key Authority.” TheRegistration Information includes the public key (PuK) and one or moreof the following types of information relating to a particular devicethat generates digital signatures: the identity of third-parties withwhich the user of the device has PuK-linked accounts for the device andrespective account identifiers that identify each PuK-linked account ofthe user to the respective third-party; information linked with thepublic key of the device in accordance with the other aspects of thepresent invention; user-specific information, such as the user's mailingaddress, credit card information, age; and, if applicable, theauthentication techniques that were employed in verifying theuser-specific information maintained by the Central Key Authority.Furthermore, the Central Key Authority preferably indexes theRegistration Information of the user to the public key of the user suchthat the Registration Information may be retrieved based on the publickey. In other words, the user of the device is an “account holder” ofthe Central Key Authority.

In accordance with this aspect of the present invention, the Central KeyAuthority disseminates some or all of the Registration Information, asappropriate or as requested, to a third-party. Registration Informationis disseminated when the user has an ABDS account with a third-party ordesires to establish a new ABDS account with a third-party—and desiresto send ECs with messages containing an instruction that represents atransaction on the account, such message being digitally signed usingthe device. The dissemination of the Registration Information occurs,for example, when Registration Information maintained by a third-partyhas become outdated for a particular account.

The Registration Information maintained by the Central Key Authority isobtained in various ways. For example, the public key and informationlinked therewith preferably is obtained from the manufacturer of thedevice or other reliable entity possessing the public key and SecurityProfile of the device. The identity of the third-parties with which theuser has PuK-linked accounts for the device, and the account identifierthat identifies the PuK-linked account of the user to each suchthird-party, preferably is obtained from the user, and is obtained whenthe user registers with the Central Key Authority; when, at theinstruction of the user, the Central Key Authority establishes anaccount on behalf of the user with a third-party; or when thethird-party, at the instruction of the user, requests the RegistrationInformation from the Central Key Authority.

An example of the convenience that may be provided by the Central KeyAuthority in accordance with this third aspect of the present inventioncomprises the updating of PuK-linked accounts of a user with a newdevice of the user in place of the user's old (and possibly outdated)device. Such an update preferably is accomplished by merely sending anEC to the Central Key Authority including the public key of the olddevice and a message including an instruction to associate an expresslyidentified public key of the new device with expressly identifiedthird-party accounts that is digitally signed using the old device.

Upon receipt of such an EC, the Central Key Authority authenticates themessage of the EC using the identified public key of the old device.Upon successful authentication, the Central Key Authority retrieves theRegistration Information for the public key corresponding with the olddevice. The Central Key Authority then updates the RegistrationInformation with the public key of the new device, and then transmits anEC to each of the third-parties expressly identified by the user, the ECrequesting each third-party to associate their respective accountrecords of the user with the public key of the new device in place ofthe previous public key of the user. The instruction preferably isdigitally signed using a private key of the Central Key Authority andmay include the original EC received by the Central Key Authority fromthe user.

The above generally-described systems are illustrated more specificallyin the following FIGS. 71 a–72. A system 7100 a in accordance with thethird aspect of the invention including a Central Key Authority 7190 anddatabase 7194 of account records is illustrated in FIG. 71 a. Onceagain, an account holder 7102 possesses a device 7150, which securelyprotects a unique private key of a public-private key pair. Preferably,the device also retains the public key (PuK1) 7118 therein, which iscapable of being exported from the device 7150. As can be seen in FIG.71 a, the public key (PuK1) of the device 7150 has been previouslyregistered with account authority 7112 and associated with an accounthaving the unique account identifier “acctID(a)” and stored in anaccount record in account database 7114 (based on the public key (PuK1)that is retrievable from database 7114 in response to input of accountnumber (acctID (a)).

The account holder 7102 also possesses another device 7151, which inthis illustration is a person-centric device, as described with regardto the second aspect of the present invention. The person-centric device7151 securely protects a different private key of a public-private keypair therein. Preferably, the device 7151 also retains the public key(PuK2) 7128 therein, which is capable of being exported from the device7151. As can be seen from the illustration in FIG. 71 a, the public key(PuK2) of the person-centric device 7151 has been registered with twodifferent account authorities: with account authority 7122, the PuK2 isassociated with an account having the unique account identifier“acctID(b)” and stored in an account record in account database 7124;and with account authority 7132, the PuK2 is associated with at leasttwo separate accounts having the unique account identifiers “acctID(c1)”and “acctID(c2).” Both accounts acctID(c1) and acctID(c2) are stored ina respective account record in account database 7134.

In establishing a database account with the Central Key Authority 7190,with reference to FIGS. 71 a and 72, the account holder 7102 preferablyprovides the Central Key Authority 7190 with the following informationfor each account to be tracked: the public key 7118,7128 of eachrespective device 7150,7151 that is associated with an account (recordedin column 7218 of FIG. 72); the unique identifier (e.g., acctID(a);acctID(b); acctID(c1); acctID(c2)) and other account-specificinformation, such as the identity of the account authority and the typeof account, for each specific account (recorded in column 7244 of FIG.72). The account holder 7102 also preferably provides customer-specific(i.e., personal) information to the Central Key Authority 7190 (recordedin column 7242 of FIG. 72) as well as device profile informationregarding each device 7150,7151 associated with such accounts (recordedin column 7240 of FIG. 72). Other account attributes may also berecorded in the account database 7194 and obtained either from theaccount holder 7102 or directly from the respective account authority7112,7122,7132. Preferably, the Central Key Authority 7190 assigns theaccount holder 7102 with a unique account identifier, such as aregistration account number “RacctID(a),” (recorded in column 7230 ofFIG. 72).

Still with reference to FIG. 71 a, account holder 7102 is capable ofcommunicating electronically with the Central Key Authority 7190 in atwo-party ABDS manner (as described with respect the first aspect of theinvention) over communications medium 7108. In other words, the accountholder 7102 may register a device 7150 or new account associated withthe person-centric device 7151 by sending the Central Key Authority 7190an electronic communication that contains a message (M) that includesthe accounts holder's Central Key Authority account number (RacctID(a))and an instruction (i3), and digital signature (DS) of the message.

The actual steps performed by the account holder 7102 and the CentralKey Authority 7190 to create, sign, send, and authenticate such amessage will not be described in detail, since such steps closely followthe methodology of a two-party ABDS communication that has beendiscusses already at great lengths. Interestingly, since the account7230 of the account holder 7102 maintained by the Central Key Authority7190 may, in fact, be associated with multiple public keys 7218, theprocess of authenticating the message potentially requires the CentralKey Authority 7190 to attempt authentication of a message using morethan one public key. Typical instructions (i3) that the account holder7102 sends to the Central Key Authority 7190 include, for example,requests initially to setup a Central Key Authority account; to add anew device 7150 or 7151 (and corresponding public key) to theRegistration Information; to add, update, or delete personal informationin the Registration Information; to add, update, or modify an accountidentifier associated with a particular account; to add a new accountauthority (and account) to an existing public key; to add or modifyinformation regarding an existing account authority, and the like.

Referring again to FIG. 72, an example of the account database 7194maintained by the Central Key Authority 7190 is illustrated, wherein thedatabase 7194 is organized by registration account ID numbers 7230 andhas associated therewith: the corresponding customer-specificinformation 7242, for example, name, address, social security numberand/or tax-ID number, credit card information; public key information7218, including each public key of the particular customer; deviceprofile information 7270 for each device that retains the private keycorresponding with each respective public key, such device profileinformation including security characteristics, authenticationcapabilities of the device, manufacturing history, and transactionalhistory; and a list of all the account(s) associated with the publickey, including the account-specific information 7244, for example, nameof the account authority, the unique account identifier (acctID)associated with the account, the address of the account authority, thetype of account maintained by the account authority, and the like.

It will be immediately apparent that the Central Key Authority 7190provides a convenient manner to keep track of a plurality of public keysassociated with a particular account holder 7102, as well as aconvenient manner of keeping track of each account associated with eachpublic key. Easy and ready access to such information is important. Forexample, especially when a person-centric device 7151 of the accountholder 7102 is lost or stolen, or the private key (Puk2) thereofcompromised, the appropriate account authorities 7122,7132 need to benotified.

In such a situation, as illustrated in FIG. 71 b, the account holder7102 notifies the Central Key Authority 7190 of such (obviously in amore conventional manner since, presumably, the device or private key(PrK2) is no longer available to originate a digital signature of themessage). The Central Key Authority 7190, in turn, contacts each accountauthority 7122,7132. Each account authority 7122,7132 then deactivatesthe associated account [acctID(b); acctID(c1); acctID(c2)] (or at leastdeactivates the use of the account by means of the particular device7151 and public key 7128) until the account holder 7102 associates a newpublic key (PuK2-new) therewith.

Furthermore, as shown in FIG. 71 c, once the account holder 7102 hasobtained a new device 7151 a and corresponding new public key (PuK2-new)7138, the account holder 7102 needs only to update the Central KeyAuthority 7190 with the new public key (PuK2-new) 7138. The Central KeyAuthority 7190 then preferably communicates the new public key(PuK2-new) 7138 to each of the appropriate account authorities 7122,7132for association therewith and reactivation of the respective accounts[acctID(b); acctID(c1); acctID(c2)].

As illustrated in FIG. 71 d, the Central Key Authority 7190 also isinstrumental in establishing a new account with a new account authority7142. In this regard, if a Central Key Authority 7190 maintains a recordfor an account holder 7102 desiring to establish an account with a newaccount authority 7142, the new account (acctID(d)) preferably isestablished by the Central Key Authority 7190 at the request of theaccount holder 7102. Specifically, the account holder 7102 instructs theCentral Key Authority 7190 to transmit the relevant information from theaccount database 7194 for the account holder 7102 to the new accountauthority 7142. Among the relevant information is included the publickey (PuK2-new) 7138 of the account holder 7102 to be associated with thenew account (acctID(d)). Subsequently, the desired account authority7142 establishes an initial record in its account database 7144 usingthe information received from the Central Key Authority 7190. Anyadditional information that may be required by the account authority7142 then may be obtained from the new account holder 7102 and the newrecord in the account database 7144 updated.

Assuming that the Central Key Authority 7190 and account authorities7112,7122,7132,7142 have registered their own public keys with eachother, then the above communications between them can occur in anelectronic communication, two-party ABDS manner as well.

4. Applying Dynamic Risk Analysis to a Transaction As will beappreciated, trust in the ABDS systems described above depends upon thelegitimate possession and use of private keys. A fraudulent use of aprivate key to digitally sign a message contained in an EC cannot bedetected merely through authentication of the message. Thus, the aboveABDS systems are potentially susceptible to fraudulent uses if a privatekey of a device is stolen, either by physical theft of the device, or bydiscovery of the private key and subsequent copying and use in anotherdevice capable of originating digital signatures.

To guard against fraudulent use of a device through theft of the deviceitself, Factor B Entity Authentication and/or Factor C EntityAuthentication techniques and requirements, described previously, areused. To guard against discovery of a private key and subsequent copyingand use in another device, devices are manufactured with electronicshielding, zeroization, auditing, tamper evidence and tamper response,and other security features that safeguard the private key (and otherprotected data) contained therein. Such security features includehardware, software, and firmware and are well known in the art ofmanufacturing secure computer chips and other cryptographic modules.

The requirements for such security features are specified in FederalInformation Processing Standards Publication 140-1, SecurityRequirements for Cryptographic Modules, US DOC/NBS, Jan. 11, 1994(herein “FIPS PUB 140-1”), which is incorporated herein by reference;Federal Information Processing Standards Publication 140-2, SecurityRequirements for Cryptographic Modules, US DOC/NBS, May 25, 2001 (herein“FIPS PUB 140-2”), which is incorporated herein by reference. FIPS PUB140-1 and 140-2 also define security levels that may be met by a devicebased on the device's security features, with each of these definedsecurity levels representing a various level of difficulty—in terms oftime and money—that would be encountered in attempting to discern aprivate key of a device. Currently, four security levels are definedwith security level 4 being the highest level of security available.

Specifications for such security features also are set forth in TrustedPlatform Module (TPM) Security Policy Version 0.45, TRUSTED COMPUTINGPLATFORM ALLIANCE, October 2000, and TCPA PC ImplementationsSpecification Version 0.95, TRUSTED COMPUTING PLATFORM ALLIANCE, Jul. 4,2001, both which are incorporated herein by reference (collectively“TCPA Documents”); and Common Criteria for Information TechnologySecurity Evaluation, Smart Card Protection Profile, Draft Version 2.1 d,SMART CARD SECURITY USER GROUP, Mar. 21, 2001, which is incorporatedherein by reference (hereinafter “Smart Car Protection Profile”).

The characteristics of a device that safeguard against discovery of aprivate key and other protected data are referred to herein as “securitycharacteristics” of the device. The characteristics of a device thatsafeguard against unauthorized use of the device by authenticating theuser are referred to herein as “authentication capabilities” of thedevice. The “security features” of a device (including a cryptographicmodule or TPM) comprise features such as the security characteristicsand authentication capabilities, the requirements for which arespecified in the above-cited references.

Unfortunately, while the aforementioned safeguards generally reduce therisk of fraud within the digital signature system overall, a recipientof any one particular EC including a message and corresponding digitalsignature may be unfamiliar with the device used to generate the digitalsignature and, therefore, be unable to gauge the risk of whether thedigital signature was generated fraudulently, either through theft ofthe device or discovery of the private key. Furthermore, a recipientgenerally is unable to gauge the risk of whether a digital signature wasgenerated fraudulently when no Secret or biometric value is sharedbetween the sender and the recipient. In such a situation, a recipientcurrently must rely upon blind trust in accepting that the device usedto generate the digital signature has not been stolen and in acceptingthat the device used to generate the digital signature has sufficientsafeguards to protect its private key from discovery and use.

Accordingly, a fourth aspect of the present invention will now bedescribed. The fourth aspect of the invention incorporates the ABDSsystem of the first aspect of the present invention and includes, inaddition thereto, the identification and evaluation of numerous factorsby an account authority for the purpose of gauging the risk orlikelihood that a message that authenticates was fraudulently,inadvertently, or unknowingly signed and for the purpose of determiningwhether the instruction (i1) contained within the message should beperformed. The factors evaluated and considered include theauthentication capabilities of the device used to originate a digitalsignature for the message, the type and sufficiency of entityauthentication, if any, obtained by the device or provided with the EC,security characteristics of the device, environmental factors associatedwith the creation and transmission of the message, transactional historyassociated with the device or relevant account associated with themessage, and other account or business-specific factors, includingwhether the instruction (i1) is capable of being performed on theidentified account (e.g., are there sufficient funds in the account tocover the requested withdrawal or transfer? Is the account holderauthorized to view the requested information? Is the account holderauthorized to enter the requested space? Is the account holderauthorized to make the requested transaction? Is the account holderauthorized to enter into the specified contract?).

Authentication capabilities of a device include those components thatperform either or both of Factors B and C Entity Authentication withregard to authentication of the user of the device. Knowing theauthentication capabilities of the device (or lack thereof) allows arecipient to gauge a likelihood of whether someone other than theauthorized user utilized the device to generate a digital signature. Itis also important to know the security characteristics of adevice-rather than simply a stated security level of the device—astechnologies are developed over time that reduce the effectiveness ofsuch security characteristics and, consequently, result in the decreaseof the actual security level of the device. Unless upgrades are made,the security characteristics of a device are permanent while thesecurity level of the device eventually will decrease over time. Byknowing the security characteristics, the appropriate security level ofa device may be determined at any given time.

Further, it is also important to know the “manufacturing history” of thedevice used to generate the digital signature contained within an EC.“Manufacturing history” of the device preferably includes a recording ofmanufacturing attributes of the device, such as the manufacturer of thedevice; all specifications applicable to the device; manufacture date ofthe device; location of manufacture; batch identifier of the device;serial number or part number of the device; security of themanufacturing facility; physical instantiation of the device regardinglayout and process geometry; software identification and release date;operating parameters of the device, including voltage and frequencyranges; and identification of all enabled hardware and software securityfeatures of the device. The manufacturing history of the device alsopreferably includes the cryptographic characteristics, key generationcharacteristics, and random number generator characteristics of thedevice. By knowing the manufacturing history of a device, the securitycharacteristics and authentication capabilities of the device may berevised as errors, omissions, flaws, security breaches, or possibleimproprieties and the like are discovered as having occurred during themanufacturing of the device. Accordingly, knowing the manufacturinghistory enables one to determine an assurance level of the device.

“Environmental factors” associated with the creation and transmission ofan EC include knowing where in the world the EC originated, how the ECwas communicated, whether and what type of I/O support element(s), ifany, were involved in the creation and transmission of the EC, whethereach such I/O support element originated its own digital signature forthe EC, the security characteristics associated with the I/O supportelement, the overall digital signature environment in which the deviceoperates, such as, for example, whether the entity authenticationinformation can be eavesdropped on by the I/O support element or otherexternal apparatuses, copied, and then replayed at a later time withoutthe device user's knowledge, and the like. “Transactional history” ofthe device or the account associated with the EC involves identifyingand tracking irregular or abnormal activity or instructions associatedwith the account (e.g., knowing the typical geographical usage of thedevice, typical transactional amounts or types, frequency of use,typical entity authentication provided, historical data regardingincorrect attempts to provide entity authentication, and the like),knowing whether a device has been reported lost or stolen, and the like.Other account factors and business considerations include all additionalcriteria evaluated by a recipient of an EC to determine whether aninstruction (i1) within a message should be performed.

As described previously with regard to each of the various ABDS systems,it is preferable that the Device Profile Information of a device berecorded by an account authority in the account database record withwhich the public key of the device is associated. The Device ProfileInformation includes the Security Profile and transactional history ofthe device. The Security Profile includes the security features andmanufacturing history of the device. The security features include thesecurity characteristics and authentication capabilities of the device.The Security Profile is preferably, but not necessarily, obtaineddirectly from the manufacturer of the device, which preferably is atrustworthy and reliable entity. If the Security Profile is not obtaineddirectly from the manufacturer, then the Security Profile is obtainedeither indirectly from a trusted third party which obtained the SecurityProfile from the manufacturer or from a physical inspection of thedevice by the account authority (or by an entity trusted by the accountauthority). The Security Profile may also be provided by the accountholder within the scope of the present invention. In view of the thirdaspect of the invention, the Security Profile also may be obtained froma Central Key Authority—such as when information is received from theCentral Key Authority in establishing a new account for an accountholder.

Equipped with this information in the Device Profile Information, anaccount authority, after authenticating a message contained within anEC, further processes the message, which includes making a calculateddetermination whether or not to execute the instruction (i1) containedin the authenticated message. Alternatively, further processing of themessage includes a decision to execute a limited portion of theinstruction based on an analysis of the current risk associated with theinstruction (i1) or to require additional information from the sender ofthe EC in order to decrease the risk associated with the currentinstruction (i1).

As illustrated in FIG. 73, for example, when an account authority firstreceives (Step 7302) an EC from an alleged account holder, it retrieves(Step 7304) from the account database the PuK associated with theaccount number provided in the EC and attempts to authenticate (Step7306) the message using the PuK. If the message does not authenticate(in Step 7308), then the account authority replies (Step 7310) with arejection of the message and/or instruction (i1) contained in themessage—all of which conforms with the first aspect of the presentinvention. If the message does authenticate (in Step 7308), then theaccount authority further processes (Step 7312) the message andinstruction (i1) contained within the message.

Examples of further processing of the message by an account authorityafter successful authentication of the message in accordance with thefirst aspect of the present invention were previously described inassociation with FIGS. 6–63 for each of the specific implementations ofthe two-party and three-party ABDS systems. As shown in FIG. 73,however, further processing (Step 7312) in accordance with this fourthaspect of the present includes evaluation and consideration (Step 7314)of numerous factors that are used by the account authority, ultimately,to determine whether or not to perform the instruction (i1) containedwithin the message. The evaluation and consideration (Step 7314)includes an evaluation (Step 7316) of the authentication capabilities ofthe device and an analysis of entity authentication, if any, provided bythe sender of the EC or user of the device, an evaluation (Step 7318) ofthe security characteristics associated with the device, an evaluation(Step 7320) of the environmental factors surrounding the EC,consideration (Step 7322) of the transactional history of the deviceand/or the account associated with the EC, and consideration (Step 7324)of other account or business-specific factors. Whether the accountauthority considers some or all of the above factors, how much weight orimportance the account authority applies to any particular factor, andthe order, if any, in which the account authority evaluates or considersthe above factors varies from one account authority to the nextaccording to each account authority's own particular business concerns,needs, objectives, purposes, and risks. Thus, each account authorityuses its own business rules and judgment to determine (Step 7326), basedon any or all of the factors considered (in Step 7314), whether theinstruction (i1) from the message should be performed. If thedetermination (in Step 7326) is negative, then the account authorityreplies (Step 7310) with a rejection of the message and/or instruction(i1) contained in the message. If the determination (in Step 7326) ispositive, then the account authority performs (Step 7328) theinstruction (i1) from the message and updates (Step 7330) the accountrecord accordingly.

Although not shown in FIG. 73, if the determination in Step 7326 isnegative, the account authority may alternatively choose to execute onlya limited portion of the instruction (i1), if possible, based on ananalysis of the above factors. In another alternative embodiment (alsonot shown in FIG. 73), the account authority may require additionalinformation from the sender of the EC prior to performing theinstruction (i1)—in order to decrease the risk associated with thecurrent instruction (i1).

From all of the above, it should be apparent that the devices describedabove with regard to the present invention encompass, for example,devices of merchants and other commercial entities that generate digitalsignatures, and are not limited to devices of individual consumers thatgenerate digital signatures. For instance, a device in accordance withthe present invention includes an I/O support element comprising, forexample, an IC card reader used to read IC cards of individual consumersin establishing secure financial transactions if such IC card readeritself generates digital signatures. In this regard, such device mayinclude a trusted platform module.

Accordingly, it readily will be understood by those persons skilled inthe art that, in view of the above detailed description of preferredembodiments, devices, and methods of the present invention, the presentinvention is susceptible of broad utility and application. Many methods,embodiments, and adaptations of the present invention other than thoseherein described, as well as many variations, modifications, andequivalent arrangements, will be apparent from or reasonably suggestedby the present invention and the following detailed description thereof,without departing from the substance or scope of the present invention.Furthermore, those of ordinary skill in the art will understand andappreciate that although steps of various processes may be shown anddescribed in some instances as being carried out in a preferred sequenceor temporal order, the steps of such processes are not necessarily to belimited to being carried out in such particular sequence or order.Rather, in many instances the steps of processes described herein may becarried out in various different sequences and orders, while stillfalling within the scope of the present invention. Accordingly, whilethe present invention is described herein in detail in relation topreferred methods and devices, it is to be understood that this detaileddescription only is illustrative and exemplary of the present inventionand is made merely for purposes of providing a full and enablingdisclosure of the invention. The detailed description set forth hereinis not intended nor is to be construed to limit the present invention orotherwise to exclude any such other embodiments, adaptations,variations, modifications and equivalent arrangements of the presentinvention, the present invention being limited solely by the claimsappended hereto and the equivalents thereof.

1. A method of communicating electronically over a communications mediumregarding an account, comprising the steps of: (a) maintaininginformation pertaining to the account in a database accessible by anauthentication component, the information being retrievable based on aunique identifier, the information including security features of agenuine device that generates digital signatures using a private key ofa public-private key pair, wherein the genuine device does not reside inand is not part of the authentication component and wherein the securityfeatures are indicative of the accessibility of the private key outsidethe genuine device; (b) associating the public key of the genuine devicewith the unique identifier such that the public key is retrievable basedon the unique identifier; (c) thereafter, (i) receiving an electroniccommunication including the unique identifier, a message, and a digitalsignature of the message, the digital signature generated by a suspectdevice and the message comprising a request pertaining to the account;(ii) authenticating the message using the public key associated with theunique identifier; (iii) upon successful authentication, identifying thesecurity features retrievable by the unique identifier as being thesecurity features of the genuine device; and (iv) acting upon theaccount in response to the request as a function of the likelihood thatthe digital signature generated by the suspect device was generated bythe genuine device based on the security features of the genuine device.2. The method of claim 1, wherein the authentication component is anaccount authority.
 3. The method of claim 1, wherein the authenticationcomponent is a central key authority.
 4. The method of claim 1, whereinthe step of maintaining the record is performed by an account authority.5. The method of claim 1, wherein the step of maintaining the record isperformed by a central key authority.
 6. The method of claim 1, whereinthe unique identifier comprises the associated public key.
 7. The methodof claim 1, wherein the unique identifier comprises an account number.8. The method of claim 1, wherein the communications medium is open andinsecure.
 9. The method of claim 1, wherein the communications mediumcomprises the Internet.
 10. The method of claim 1, wherein theinformation includes at least one of the name, address, social securitynumber, and tax identification number of the account holder.
 11. Themethod of claim 1, wherein the information includes a current balance oran available credit for the account.
 12. The method of claim 1, whereinthe information includes a list of associated accounts.
 13. The methodof claim 1, wherein the security features for each of a plurality ofgenuine devices are indexed in the database to the public key of eachrespective device.
 14. The method of claim 1, wherein the securityfeatures for each of a plurality of genuine devices are indexed in thedatabase to a respective unique identifier.
 15. The method of claim 1,wherein the step of acting upon the account is conditioned upon therequest and a corresponding minimum likelihood determination that thedigital signature was generated by the genuine device associated withthe request.
 16. The method of claim 1, wherein the step of acting uponthe account is conditioned upon the account and a corresponding minimumlikelihood determination that the digital signature was generated by thegenuine device associated with the account.
 17. In a system forauthenticating an account holder for access to an account of the accountholder in which access to the account is controlled by an authenticationcomponent, wherein the account holder possesses a secure device thatmaintains therein a private key of a public-private key pair, a methodcomprising the steps of: (a) maintaining in a database informationpertaining to the account, the information being retrievable based on aunique identifier of the account holder; (b) associating the public keyof the public-private key pair with the account such that the public keyis retrievable based on the unique identifier; (c) associating asecurity profile of the secure device with the account such that thesecurity profile is retrievable based on the unique identifier, thesecurity profile identifying security features of the secure device, thesecurity features indicative of the privacy and uniqueness of theprivate key; (d) wherein the authentication component performs the stepsof: (i) receiving an electronic communication including the uniqueidentifier, a message, and a digital signature of the message, thedigital signature generated by a suspect device and the messagecomprising a request pertaining to the account; (ii) based on the uniqueidentifier from the electronic communication, obtaining the public keyand the security profile of the secure device; (iii) using the publickey obtained from the database, decrypting the digital signature toverify that the digital signature was generated using the private key ofthe secure device; and (iv) determining the likelihood that the digitalsignature generated by the suspect device was actually generated by thesecure device based on the security features of the secure device; and(e) acting upon the request as a function of said determination.
 18. Themethod of claim 17, wherein the step of acting upon the request isfurther conditioned upon the nature of the request and a minimumlikelihood required determination associated with request.
 19. Themethod of claim 18, wherein the step of acting upon the request isconditioned upon the account and a minimum likelihood requireddetermination associated with the account.
 20. A method of communicatingelectronically over a communications medium regarding an account,comprising the steps of: (a) maintaining information pertaining to theaccount in a database such that the information is retrievable by aunique identifier, the information including security features of agenuine device that generates digital signatures using a private key ofa public-private key pair, the security features indicative of thesecurity of the private key of the genuine device relative to otherdevices capable of generating digital signatures; (b) associating thepublic key of the genuine device with the unique identifier in thedatabase; (c) receiving an electronic communication including the uniqueidentifier and a digital signature for a message generated by a suspectdevice; (d) authenticating the message using the public key associatedwith the unique identifier; (e) upon successful authentication of themessage, identifying the security features retrievable by the uniqueidentifier as being the security features of the genuine device; and (f)gauging the risk that the private key of the genuine device wascompromised based on the identified security features of the genuinedevice.